It's possible, but there are so many other possibilities that it can't be guaranteed.

things like:
- what else is on your site besides Zen Cart? (forum, blog, gallery, other things)
- what mods have you installed to Zen Cart?
- are there any rogue files on your server that you haven't discovered yet which might be causing this bad behaviour?
- then there's server-side issues over which you have no control, etc