To all those (like mingistech) who are noticing differences in the output modes to their TVs, please download this binary and replace the one in XBMC.app/Contents/MacOS. Then run from the command line:
$ ./XBMC.app/Contents/MacOS/XBMC
Please paste the entire output in the Terminal into this site and then post a link in the comments. The binary has lots of diagnostic output and also adds an extra check into the mode selection, making sure it’s compatible with TVs (in theory, at least). You might not notice any difference, and actually this new code may cause your TV to catch on fire. Have water handy.
Also, cullman was kind enough to write up an excellent FAQ. Please read it before you ask any questions. If we catch you asking a question that’s already been answered, no matter how obtusely, we will make endless fun of you, and the next time I’m spear-fishing I’ll name the fish after you before I stick it with my spear.