Notices

My N900 can't play video files in its own player it says media format unsupported (for any file) and also when i try to start recording a video using its camera at the moment of pressing the record key, the application dies and shows a operation failed message.
how can i solve this problem?

Do you overclock? Any speedpatch/batterypatch installed?

Could you upload your dmesg:

open terminal and type: "dmesg > you_name_it.log" and upload the file here.

Please check if there any problems with disk/RAM space

both of speedpatch/batterypatch are installed,

don't see any problem

well, it seems you have libgstdsp.so from 720p thread, but codecs are not there. NFC how did you manage to do that, but anyway - go to 720p thread and either repeat all of the steps there, or follow the steps to remove 720p

And in addition a friendly piece of advice - remove both battery patch and speedpatch, see my signature for stuff that really works and is not some placebo

Ah, and in addition:

Do not use ramzswap, remove it immediately, for some reason on n900 it not only does not give benefit, but also slows the device down a lot.

thank you freemangordon, that worked for me perfectly, but about those patches, by default my battery only works for only one day long and i was lookin for a patch which could help me to increase the battery life, i found these two, but as your saying they are not good, what do you suggest me to do to enhance the battery lifetime?

same here...
i have problem with my camera. when i open lens cover and choose camera, it said "operation failed".
When i try use my flashlight, it said " camera in use by another aplication".
can anyone help me please....
Maybe this is the problem?
http://cdn-u.kaskus.co.id/85/lmkobkir.png

Well, for start remove speedpatch/batterypatch and ramzswap

Then use "default" profile (kernel-config default default), it will enable SmartReflex, which should give you descent battery life. Have in mind that "default" profile don't overclock, if you want to overclock, use "dsp" profile as default.

If you continue to suffer from bad battery life, there is "powertop" utility, you can use it to check which process wakes up your CPU and eats the battery charge. Search the forum for similar threads, you are not the first to encounter short battery life because of the runaway process or badly written desktop widget.

If you are not using CSSU, now it is time to start . It is up to you to decide which flavor to install, read the wiki for -stable and -testing.

If you are adventurous you may want to try CSSU-thumb (see my signature), you won't believe how fast you n900 will become.

Also have in mind that battery life highly depends on your usage pattern, if you have for example several IM accounts online all day long, constant internet connection via 3G, etc, you cannot expect your battery to last 4 days.