Ubuntu :: Weird Brake-down Of System?

since yesterday my 11.04 system behaves real strange. Firstly, i can not use any of my external storage media anymore (detachable cd-rom among them). On several devices i tried to mount, they would not appear in /media/ dir, neither could i see them in Nautilus. I know that the system does recognize them in the usual fashion as before, which i can see in system.log and for example GParted.

The other thing is i can't access my trash anymore - when clicking on it in Nautilus, i get the "Sorry, could not display all the contents of "trash": Operation not supported" message. Last obvious and weird thing was that my Ubuntu One panel personalizations i have made since installing are gone (that is adding and removing icons from there) - it is back to the "original" state which was just after installation.

I didn't notice anything else obvious - apart from the things already mentioned, system seems to work fine.The worthy of mentioning things i've done before these failures was the downloading of system updates and installing of some software (tex-base, monkeyaudio codec, DropBox; actually i've got a shadow of doubt cast on this last one, since installing it required some changes to Nautilus). I don't have any previous kernel to try to load.

Since it's been only a month of usage of ubuntu on my new machine reinstalling it wouldn't hurt me so much, but i would really fancy to find out the root of this strange behavior of the system i am experiencing.