Re: When non-admin looks at Structures listing, Modules misbehave
Ok, then one last theme change and I'm about ready to shut up shop. Try "Fivealive", I'm pretty sure that is one of the latest and greatest in terms of themes. (it's the one this site uses). This will tell us if it's a theme issue or a bug (or some combination thereof). You could also try different browsers if you have them available e.g. use Firefox instead of Internet Explorer. This is all in the interests of discovering the source of the problem, nobody is expecting you to permanently switch browsers to be able to use Tiki. 
Having thought it about it some more I actually think you have two issues going on here (or maybe not). If the right hand modules are disappearing completely then that would tend to indicate some kind of permissions problem. Double-check tiki-admin.php?page=module page, and also make sure that for the right hand modules you've given permission to non-admin users to use them.
Tiki can be very infuriating at times but so many times I've found the issue to be something simple to resolve in the end.
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