Font problem in Gaim chat window

There may be weired font in Gaim MSN chat window, but gtalk works well at the same time.

The reason is MSN protocol messages carry font information along with the text. The Gaim tries to display accordingly. When there is no exact font in your machine, Gaim (or the font rendering system) will try to find a replacement which may not be the same as your system font configuration.

To revolve this problem, just go to "Tools->Preferences" and uncheck the "Show formatting on incoming messages".