Muerto -- I just upgraded to NS 4.74, and I haven't had a problem, yet, not even those annoying "illegal operation" messages that kill the program, but not Windows. It's also much faster.
That said, I had no problem editing my profile in NS 4.73, either, except that it takes a while to load, probably because of all those icon images. At first, I thought my system was hung, too, but try it again, and allow a really long time for the page to load. On my system, it doesn't display anything but the white background until most of the page is loaded.
Another thing that seems to help is regularly clearing your cache and nuking anything left in your C:\WINDOWS\TEMP directory.
Zuni -- I'm probably at least as biased against Micro$loth (the software Borg) as you seem to be against NS. NS wasn't the company stupid enough to make the default of one of the biggest security holes in history, Visual Basic Script Hosting, enabled on installation, even though they were warned well in advance of the potential problems. CIH, Happy99, Melissa and I Love You viruses would never have happened without VBS.
MS hasn't issued anything better than a buggy virus since DOS 6.22, when they finally got everything they stole from DR-DOS working. :Q
Welcome to the buggy world of Micro$loth.