I was upgrading from xorg 7.1 to 7.3 and when xorg-server started emerging, the build threw an error when compiling one of the "main.c" files. It was a syntax error resulting from the fact that the version component variables passed through -D to the preprocessor were not defined. I upgraded to the xorg 7.2 ebuild and re-merged 7.3, and xorg-server merged fine. (I'm sorry but I no longer have the error output and can't reproduce it at the moment.) This may have to do with the fact that I upgraded xorg-server separately from the rest of xorg to 1.3, so my packages were xorg 7.1 + xorg-server 1.3.
Well, if you can't reproduce it any more, and can't provide any errors, then I'm afraid there's nothing we could do.
