Mplayer, GTK2 and gcc33

[FreeBSD User]

FreeBSD fortytwo.zapto.org 4.10-STABLE FreeBSD 4.10-STABLE #0: Sun Aug
15 23:13:02 EDT 2004    
root at fortytwo.zapto.org:/usr/obj/usr/src/sys/FORTYTWO  i386
# $FreeBSD: ports/multimedia/mplayer/Makefile,v 1.101 2004/08/16
09:43:58 vs Exp $

usr/ports/multimedia/mplayer/Makefile

.if defined(WITH_GTK2) && !defined(WITH_GTK1) && !defined(WITHOUT_GUI)
.if ( ${OSVERSION} < 500000 )
USE_GCC=        3.3
.endif

I'm not understanding why, WITH_GTK2 requires GCC3.3 with mplayer,
when all my other GTK2 apps are fine with the base GCC-2.95.4.

Is there something special about mplayer, is the GCC version upto the
maintainer?

Also, is having the two version of GCC on the same system going to
cause any problems, or gotchas to look out for?

.if defined(WITH_GTK2) && !defined(WITH_GTK1) && !defined(WITHOUT_GUI)
.if ( ${OSVERSION} < 500000 )
USE_GCC=        3.3
.endif

Thanks.