Sparc mozilla 1.7, which to download?

I have just upgraded my Sparc mozilla 1.6b to 1.7, it took quite a
while because two out of the three versions on the www.mozilla,org
site didn't work for me.  I seem to remember I had similar problems
with 1.6 (and it's why I stayed at 1.6b, I never found a 1.6 that
worked).

The symptom I get (on the non working versions) is that mozilla loads,
the window frame appears and then it hangs.

Can anyone explain what the differences are and how I can avoid the
'suck it and see' approach next time?

-- 
Chris Green