I don't really want to enter into a Vista debate.
But...
I also thought that upgrading to Vista was a waste of time and would be a lot of hastle.
But I was wrong. I don't personally know of ANYONE who has had any problems at all, the drivers that were not present on the installation disc - were on the first online update.
I have heard of a lot of scare stories, but from my experience thats all they are turning out to be - stories.
If you like, you can download Vista from Microsoft, try it out for 30 days. If you don't like it then go back you don't want to update or think that its got compatibility problems.
One thing is fo sure, Vista is here now. If you want your libraries to maintain their credibility and reputation, I suggest you try figure out whats gone wrong - rather than an "I'm alright Jack" response...
The only problem I have found with some of my own PureBasic code is that I didn't code by some of the rules anyway. It was just a coincidence that they didn't crash on XP or below. I am glad that they have made the OS stricter on memory access, etc. This makes it less likely that a bad program will interfere with others and we will have less false bugs and more chance of finding out where problems really are.
My offer of helping you to make your libraries work with Vista still stands, I'd prefer that to writing my own.
I know you want to hide your source code, but there must be a way for us to fix the problem that will protect your source?