Create another user account and login into that user account. See if pidgin blocks there as well.
From your description it is not clear if the problem happens only on your account or for all user accounts. If it only happens on your account, then some of the config files is misfitted, so you should remove everything pidgin-related from your home directory.
If the problem happens on all user accounts, then the given version pidgin is buggy (can happen), so either update or remove completely and switch to some other messenger app.
Last edited by Tinkster; 10-30-2010 at 03:26 PM.