well, if they're you're own objects, then it could always be faulty coding.
Acutally, you should also consider that you're using a specific language which generally isn't cross-browser compatible. Are you sure that your target audience uses Internet Explorer, no exceptions? Otherwise, many things that are VBScript or Windows Scripts will not work.
Just a helpful hint. As for the coding problem, I don't have many ideas on how to solve it. Sorry.