Hi!
Developer extension has studied the subject and did not see his side.
"What you could do to find the problem is start with a fresh setup with only Tabs/Sliders installed. See if it works ok (if not, then it must be a server thing).
And then add the 3rd party stuff (template/extensions) one-by-one till you see the urls break."
www.nonumber.nl/forum/Tabs/13297-Tabs---...it=10&start=10#13482
Please for more help. RokSprocket as crazy an option tabs.
Best Regards!