I read the replies -- suggest the following:

Use the tool "Helpkit COM Assistant" to read the active-x and build a help file. This will give you the parameters that the active x are actually trying to use. This is to check your calling syntax.

Place the statement that causes an error into a TRY - ENDTRY block and catch the exception. Then place a SET STEP ON and see what the specific text is from the catch. This may give more information than what you have now.