On Thu, 2009-07-02 at 21:34 +0100, Peter Alcibiades wrote:
System.ArgumentNullException
Looking this up, it's a .NET Framework exception, which is unusual on a Linux box :) I suggest you use synaptic to locate anything that depends on mono-runtime which is currently installed as there should be very few such applications on a typical machine, then you should have found your culprit for this message at least.
Could not read Pidgin buddy list file:
Again - use synaptic to locate installed applications that depend on pidgin (there shouldn't be any since you purged pidgin) and libpurple0 (since that's what owns the ~/.purple folder and below). Either you will find broken dependancies or the offending application.
All this assumes you haven't just shoved random code onto your machine, ie: that everything you have installed used dpkg or a front-end such as synaptic, apt, aptitude.
Finally, you can monitor file access (a la Filemon) using the technique described here: http://ubuntuforums.org/showthread.php?p=2415252#post2415252
If you re-create the target file (/home/peter/.purple/blist.xml), then obtain it's inode (ls -i /home/peter/.purple/blist.xml), the block dump output should identify the application that is accessing said file.
HTH, Phil.