One day I was chatting with another folk (I was on Office Communicator 2007 and he was on Communicator 2005), suddenly he asked "why you keeping change font?". Then he sent me a screenshot of his IM chatting window. In this picture I saw my messages in two different fonts: the first half are in Arial, the second half are in Chinese font.
From my side, the font in messages show the same. But instead, the font of the sender's name changed.
I have Chinese MUI installed on the machine. Could my typing method causing the problem?
And why the font changed automatically? I didn't do any change on the font setting in IM client.