Comment 3 for bug 461209

Just in case anyone else finds their way here before finding a solution. There is useful information in the plugin's bug tracker:

http://code.google.com/p/pidgin-facebookchat/issues/detail?id=246

In particular, I found that the recommendation to disable the option called "Show Facebook notifications as emails in Pidgin" helped, but did not solve the problem completely.

On the other hand, using the XMPP protocol (for instructions visit http://www.facebook.com/sitetour/chat.php ), as recommended in http://code.google.com/p/pidgin-facebookchat/issues/detail?id=246#c140 , works reliably, albeit with less features.