I use use the old gcc-2.7.2.3 to compile linux kernel and it works just fine.
If you installed egcs-1.1.1 it just overwritten your files in /usr/bin(if you used --prefix=/usr) but the /usr/lib/gcc-lib/ still has the old ones there.

I had a problem in compiling glibc-2.1 with the latest egcs snapshots(19990208 and 19990131). It seems that it breaks something in memcmp and in glob. Does anyone has idea about this?