libavcodec miscompiled - running very slow

[Da Rock]

I installed gmencoder on 6.3 recently (and yes, given that I recently
posted all my ports are up to date), but when I run it to encode a movie
it comes back on the 2nd pass and says that libavcodec was miscompiled
and will be slow (sure is- runs forever getting nowhere).

It did recommend compiling on gcc>=4.2, so I installed gcc42 (tried 4.4
and 4.3, but hit issues which I wasn't prepared to overcome especially
after a quick search online) and symlinked it to the /usr/bin (renamed
the old gcc). But after reinstalling gmencoder, mencoder, and mplayer I
still had no success.

Any ideas on how to fix this? If I run gcc -dumpversion it comes back
with 4.2.4, and searching online I found that ports uses the $path to
find gcc, so I'm kinda at a loss here.