Developers can't possibly test every possible combination of hardware, software and operating system. They really have no choice but to decide which platforms to support and make no guarantees about the rest. 
 
Of course, - theoretically - everything is supposed to just work, as long as both host and plugin precisely conform to the interface spec. Yet plugin vendors routinely run into specific problems with FL Studio, ProTools, SONAR, Reaper, Studio One and Cubase - and apparently Sound Forge as well. VST is a weak specification and all it takes is for a host to interpret one of its many ambiguities a little differently than a plugin vendor and problems will ensue.
 
It's not even necessarily a case of a vendor failing to conform to the spec. It could be that the spec is incomplete, vague or ambiguous. I would not be at all surprised if Steinberg's own coders don't deal with the same issues internally. While it's true that "Steinberg decides what the VST standard is", they cannot arbitrarily redefine it, and whatever limitations are in it they have to live with like everyone else. 
 
 
 

I understand that vendors do things different, and I'd be ok with "Oh there's a bug with Sound Forge, we'll look at it." However his response that they "don't implement VST standard correctly" and then that is is unsupported is silly. Clearly it is implemented well enough to load the plugins, also it is implemented well enough for other plugins to work properly, including free ones like LoudMax. He's got a code bug and isn't willing to admit/fix it and that rather annoys me, given that this was no inexpensive.

A bunch of the presets start with one hundred percent dry mix... meaning no effect. Slide the bar towards wet in edit mode.

So it turns out to work fine in Sound Forge 10. That is very strange. For the moment, that's an acceptable solution, I have licenses for both versions.
 
Still having issues in Sonar with the VST2. It just seems to interrupt MIDI notes from playing, for whatever reason. Happening on Hailion Sonic, and Synthmaster at the very least.
 
gswitz: As I noted this is a case where I hear the sound I want in preview mode, but it doesn't apply when I hit ok. I already found out about the dry mix thing when I first started playing with it :).

Test Melda MSpectralDynamics
I've tried it in both Sonar Platinum Dorchester and Sound Forge 11
Method:
Select a single mono audio track and select a pre-set that strongly effects the track content(solo female vocal).
result: Sonar - audio processed both live and could be bounced with effect as expected.
 
result SF 11: - when previewed, effect changes were heard. On processing the audio through the fx SF11 gave every indication that audio was being processed but on listening back no effect had been committed to the file.
 
That's a bit sad. I have SF10 but I'm not going to go to the trouble of installing it for this test as it seems someone has already indicated that it works in that version.