Problens with the Plus (+) sign. Is this browser related (Opera 10.10) ?

Has anybody else encountered the following problem: In my posts plus signs (+) disappear completely. The following line should read A plus B, but I actually get A B. A + B This happens even when code or source-tagging: (Code):

A + B

(source) So: Do you see the plus signs above, or not ? I'm using Opera 10.10 on Windows XP. I had to resort to +, like this: A + B then it works, but this is a major inconvenience. unbird