ave yoy tried uninstalling any of ur apps? start with the largesst first, to do it in xterm as root type apt-get remove (name of app) and then apt-get clean to remove any leftovers.
It is always best to install or remove one app at a time that way ones with any potential problems are easilt identified

Also there is no virus in extras devel, it should work fine along side all other catalogues including devel,
however once you sort out this problem either through manualy deleting files or through a full reflash i suggest you leave the testing and devel repo's alone,
testing is not so bad, but anyone regularly installing from extras devel should first know how to and secondly be prepared to reflash
the warnings are plain to see and if u missed them u have been told now devel can seriously mess up your phone