In another forum I got a reply saying: "VBScript uses a signed INT to enumerate variables, which suggests that the maximum number of variables will be 32767"
But I think it is actually counting either the executable lines, or the actual jumping in and out of code, meaning between HTML code and VBScript code.
So since I have a main page with Select case to separate modules, but the modules are joined in using sharp includes of other asp pages, and then those have similar structure again, and they all call back to the main page, and the chain of selects determine what actual page content is displayed.
So my conclusion is that the total amount of code that could execute in each page call has exceeded some variable's maximum, and I'll need to replace at the root level the sharp includes with response redirects in order to break the modules off to have separate executions from the root and other modules.
The dissapointing part is that I can't find anything on this on Microsoft's site regarding VBScript's limitations.