I primarly use Absynth 4, FM8, Battery 3, MOTU and HSO. So, yes, these are the primary VSTs I use regularly (at least for now). The VST load hanging issue happens on any of them and is basically random. Although, I can't recall seeing it happening on HSO. But, that doesn't mean it won't or can't happen on it.

As far as the problems with VST loading, it seems to happen randomly on any of the VSTs that are in the loading chain. When the loading panel appears, the blue bar begins moving (somewhat). Then, the bar just stops moving and hangs in place, a VST is listed in the panel that it appears to be trying to load. Although, I know from experience that could mean failure trying to load the next VST rather than the current one shown. Worse, Cubase 4 then starts messing with CPU load and the audio system as the machine begins hanging in intervals (stop/start) and the audio buffer begins hanging in loop on and off (if anything happens to be playing in Winamp). It takes me several tries and a bunch of fiddling to get the 'Application not responding' panel to appear to finally get Cubase 4 killed. Even once I click 'End Now' it takes some time before Cubase 4 actually closes. Thankfully, it does.

As I said, it doesn't do this in Cubase SX 3. I've only once ever had VSTs hang on loading in SX 3 and I believe it had to do with trying to load a project after having tried to load multiple projects in the app at once (a known bug).

It's funny, I can work in SX 3 right now without issue. I cannot load Cubase 4 and work in it at all until I reboot. The system is still has the 'no sound' state from earlier and won't play any sound out of Cubase 4. Yes, I still need to reboot. Cubase SX 3 operates without any issues, however. Although, I can't load any Cubase 4 projects in SX 3, obviously.