Thanks for sharing the information, this may help with finding a fix.
Don't have this issue myself, using Windows Live Messenger 2011 though. Would like to know if more users with Windows Live Messenger 2009 have this problem, or if other users with Windows Live Messenger 2011 do.
quote:
Originally posted by amaranthine
On an added note, when I exceed the 1000 character limit, it does now send it as a .txt file (only if I exceed the exceeded character limit. If I type something above 400 but not quite over 1000 then it gives me the error).
For now you may want to disable the extended character limit feature, forcing messages containing more than 400 characters to be sent as temporary .txt file as well, instead of giving an error.
From my personal experience with these bugs and similar ones, I've realized that both MSN Messenger and Windows Live Messenger (and/or their respective connection methods) have been giving me odd bugs at random times. Some of these bugs include getting error messages returned when trying to send any text messages, contacts appearing off line, file transfers not being shown and many more similar bugs. Therefore I believe it could always be the Windows Live Messenging service acting up.
/ 
