Well, if you've got VB, it may be worthwhile to check to see if the sample code actually works. It's not unheard of for vendor-supplied sample code to be slightly buggy.

It would also be beneficial to tell the monks what the proprietary product is; one of the monks may have dealt with it, or be currently trying to use it. Heck, it's not impossible one of the monks wrote the dll.

Also, The Nameless One is correct, in that the error messages may contain useful information, so show them to us, too.

Generally, the more relevant information you supply, the more likely it is you'll get a useful answer.