I've been using NS 4.08 and NS 4.51 without any trouble for 3 years. Yeah they are old, but they work time after time. If you visit pages with a lot of DHTML scripts or interesting IE effects you'll be at a loss. DHTML doesn't show up too well in Netscape, and some DHTML scripts will crash it. Other known problems include:
HTML tags that are not closed will stop the browser there and then. The page might load half-way, but that's it.
Java apps can crash it.
Some sites will not look good if they're using CSS 2 for formatting. CSS 1 does show up, but some tags aren't recognized.
Netcrap 6 is quite possibly the biggest downloadable bug known to man. I tried it for all of a day before getting rid of it. Took too long to load and crashed when it felt like. On antique systems Netscape 4.6 or higher won't run properly. 4.6x had my system doing funny things for weeks before I settled with 4.51 and 4.08. Why have a double install? I don't know, but I've got both versions installed now for some reason.
I wouldn't go web roaming with anything less than 4.51, but on this bucket of bolts it's tempermental. A download link for 4.51 is below.
ftp://ftp.download.com/pub/communicator/ccsetup32s.exe
You can try 4.77 and see what happens, but it just chewed up too much memory for me to use. I usually have AIM open, along with 4 NS windows. 4.77 wouldn't let me do that because it gobbled up my RAM. Still, give that one a shot and see what happens. If for some reason you want to try something a bit older, try 4.51 just for the heck of it.
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Flakbait [Delta6]
Delta Six's Flight SchoolPut the P-61B in Aces High"For yay did the sky darken, and split open and spew forth fire, and
through the smoke rode the Four Wurgers of the Apocalypse.
And on their canopies was tattooed the number of the Beast, and the
number was 190." Jedi, Verse Five, Capter Two, The Book of Dweeb