Very Computer

I'm running RedHat 5.2 with developmental kernels,
currently 2.1.130 because I have dual processors, PnP,
need access to NTFS partitions, etc.  But Netscape 4.5
is crashing so often that I am reminded of Windows 3.0,
heavens forbid.  Am I the only one with these experiences??
I do a lot of email/web related work with other mathematicians/
scientists all around the world, so the email/browser
part of the os is important.  In the background, I have serious
computations going on, but it is the routine web related stuff
in the foreground that is driving me nuts.  Is there an
alternative to Netscape for Linux?  I need a bulletproof
email/browser combination and Netscape doesn't seem
to be the answer.
Thanks for any pointers. Tom T.