For what it’s worth, I recently upgraded to 6 from 5.5, and 6 is FAR less buggy than 5.5 was on my Windows ME machine. First of all, as soon as I can get my hands on a copy of Windows 2000, I’m installing it, because I hate Windows ME. But also, I think IE 5.5 has some serious compatibility problems with WinME, because otherwise I can’t explain all the weird bugs I was having before. For example, View Source wasn’t working. I’d click View Source and absolutely nothing would happen. And occasionally I’d be viewing a web page, and Explorer would shut down for no reason and with no warning. There was some other weird stuff as well. All seemingly fixed with the upgrade to 6.
I’ll have to ask MrWhatsit (He Who Programs) about the Java implementation, as it is something I know nothing about.