hi all,
how are u all.i have some IRRITATING problems when i update/upgrade apps via x-terminal.i m just a N900 user not a programmer so i dont know either these are problems or not.
you can see below my problems & questions.

when i check for updates (apt-get update),i get:

Nokia-N900:~# apt-get update
Hit http://repository.maemo.org fremantle-1.3 Release.gpg
Get:1 https://downloads.maemo.nokia.com ./ Release.gpg [198B]
Ign http://repository.maemo.org fremantle-1.3/free Translation-en_GB
Ign http://repository.maemo.org fremantle-1.3/non-free Translation-en_GB
Ign https://downloads.maemo.nokia.com ./ Translation-en_GB
Hit http://repository.maemo.org fremantle Release.gpg
Get:2 https://downloads.maemo.nokia.com ./ Release.gpg [198B]
Ign http://repository.maemo.org fremantle/free Translation-en_GB
Ign https://downloads.maemo.nokia.com ./ Translation-en_GB
Ign http://repository.maemo.org fremantle/non-free Translation-en_GB
Ign http://my-maemo.com fremantle Release.gpg
Ign http://my-maemo.com fremantle/user Translation-en_GB
Get:3 https://downloads.maemo.nokia.com ./ Release.gpg [198B]
Hit http://marmistrz.net63.net fremantle Release.gpg
Ign https://downloads.maemo.nokia.com ./ Translation-en_GB
Ign http://marmistrz.net63.net fremantle/stable Translation-en_GB
Hit https://downloads.maemo.nokia.com ./ Release
Hit https://downloads.maemo.nokia.com ./ Release
Ign http://marmistrz.net63.net fremantle/testing Translation-en_GB
Hit https://downloads.maemo.nokia.com ./ Release
Err https://downloads.maemo.nokia.com ./ Release

Get:4 https://downloads.maemo.nokia.com ./ Release [507B]
Get:5 https://downloads.maemo.nokia.com ./ Release [507B]
Ign https://downloads.maemo.nokia.com ./ Release
Ign http://marmistrz.net63.net fremantle/unstable Translation-en_GB
Get:6 https://downloads.maemo.nokia.com ./ Release [507B]
Ign https://downloads.maemo.nokia.com ./ Release
Ign https://downloads.maemo.nokia.com ./ Release
Hit http://repository.maemo.org fremantle-1.3 Release
Ign https://downloads.maemo.nokia.com ./ Packages/DiffIndex
Hit http://repository.maemo.org fremantle Release
Ign http://my-maemo.com fremantle Release
Ign https://downloads.maemo.nokia.com ./ Packages/DiffIndex
Hit http://marmistrz.net63.net fremantle Release
Ign http://repository.maemo.org fremantle-1.3/free Packages/DiffIndex
Ign https://downloads.maemo.nokia.com ./ Packages/DiffIndex
Ign http://repository.maemo.org fremantle-1.3/non-free Packages/DiffIndex
Ign http://repository.maemo.org fremantle/free Packages/DiffIndex
Ign https://downloads.maemo.nokia.com ./ Packages
Ign http://repository.maemo.org fremantle/non-free Packages/DiffIndex
Ign http://my-maemo.com fremantle/user Packages/DiffIndex
Ign https://downloads.maemo.nokia.com ./ Packages
Ign http://marmistrz.net63.net fremantle/stable Packages/DiffIndex
Ign https://downloads.maemo.nokia.com ./ Packages
Hit https://downloads.maemo.nokia.com ./ Packages
Hit https://downloads.maemo.nokia.com ./ Packages
Ign http://marmistrz.net63.net fremantle/testing Packages/DiffIndex
Hit https://downloads.maemo.nokia.com ./ Packages
Ign http://marmistrz.net63.net fremantle/unstable Packages/DiffIndex
Hit http://repository.maemo.org fremantle-1.3/free Packages
Hit http://repository.maemo.org fremantle-1.3/non-free Packages
Hit http://repository.maemo.org fremantle/free Packages
Hit http://repository.maemo.org fremantle/non-free Packages
Ign http://my-maemo.com fremantle/user Packages
Hit http://marmistrz.net63.net fremantle/stable Packages
Hit http://marmistrz.net63.net fremantle/testing Packages
Hit http://marmistrz.net63.net fremantle/unstable Packages
Ign http://my-maemo.com fremantle/user Packages
Hit http://my-maemo.com fremantle/user Packages
Fetched 2115B in 25s (83B/s)
Reading package lists... Done
W: GPG error: https://downloads.maemo.nokia.com ./ Release: The following signatures were invalid: KEYEXPIRED 1349249546 KEYEXPIRED 1349249546 KEYEXPIRED 1349249546
W: GPG error: https://downloads.maemo.nokia.com ./ Release: The following signatures were invalid: KEYEXPIRED 1349249546 KEYEXPIRED 1349249546 KEYEXPIRED 1349249546
W: GPG error: https://downloads.maemo.nokia.com ./ Release: The following signatures were invalid: KEYEXPIRED 1349249546 KEYEXPIRED 1349249546 KEYEXPIRED 1349249546
W: You may want to run apt-get update to correct these problems

you can see above GPG error,KEYEXPIRED,signatures were invalid,you may want to run apt-get update to correct these problems,is all of these are ok? (Q.1)
if its not ok then please tell me solutions & suggestions


for updating apps i used (apt-get upgrade)
Nokia-N900:~# apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages have been kept back:
libgcc1 libsdl-mixer1.2 libstdc++6
The following packages will be upgraded:
xarchiver
1 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
Need to get 0B/384kB of archives.
After this operation, 803kB disk space will be freed.
Do you want to continue [Y/n]? y
WARNING: The following packages cannot be authenticated!
xarchiver
Install these packages without verification [y/N]? y
(Reading database ... 35112 files and directories currently installed.)
Preparing to replace xarchiver 0.4.6-7maemo2 (using .../xarchiver_0.4.6-7maemo2_all.deb) ...
Unpacking replacement xarchiver ...
Processing triggers for catoriseplus ...
################################################## #############################################
No changes to hildon menu.
Setting up xarchiver (0.4.6-7maemo2) ...
Unknown media type in type 'sketch/png'

xarchiever is upgraded & What is about processing triggers for catoriseplus #######? (Q.2)
it shows me this everytime when i upgrade any application.

again checking for updates (apt-get upgrade)
Nokia-N900:~#
Nokia-N900:~# apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages have been kept back:
libgcc1 libsdl-mixer1.2 libstdc++6
The following packages will be upgraded:
xarchiver
1 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
Need to get 0B/384kB of archives.
After this operation, 803kB disk space will be freed.
Do you want to continue [Y/n]?

now it is showing me again update for xarchiever thats i hate the most when i get update notification for xarchiever everyday

so please tell me if above mentioned are problems then how can i solve them.
my last question (Q.3):
i m using CSSU stable & i want to migrate from stable to testing (specially for thumb) so i want to know how can i do this.I have to disable the stable repository ? or something else like that ?

it is not compulsory/necessary to get all answers in 1 post or by 1 user,if u know about anyone of above then please tell me
help will be much appreciated