I upgraded my device to PR1.1 and with that my Qt development setup is not working anymore.

When I transfer my binary to the device and try to run it with run-standalone, it doesn't work like it used to do. I get an error like this:

"Cannot mix incompatible Qt library (version 0x40503) with this library (version 0x40601) - Aborted"

I tried then apt-get update and apt-get upgrade, which showed me that there is a new version to download. When trying to download that, it stops with an error like this:

"Failed to fetch downloads.maemo.nokia.com/maemo-launcher-0.35 Size mismatch"

Then I tried to upgrade my SDK, but ran into problems as well:

"Processing was halted because there were too many errors.
E: Sub-process /scratchbox/devkits/debian-etch/bin/dpkg returned an error code (1)"

I am end up with a non working development environment. Any ideas?

Probably you are using Qt 4.6 (or vice-versa) and one of the dependencies of your application is not installed for Qt4.6, so the system tries to use the installed Qt4.5 version.

You can try to install the missing dependency again, since the repositories were down, or link your app exclusively against Qt4.5 (or the version that you've in the device).