I haven't experienced your problem but a quick Google search returned a few forum posts by people who did ...
Unfortunately, the general consensus was that if you hard reset (or flash) your TP, anything on the software side that might affect the slide-triggered rotation would be overwritten... If the problem persists, the device is most likely faulty.
Since you already tried a few ROMs and the problem is still there ... I think it's safe to assume it's warranty time.
Again, it was just a quick Google search so I could be wrong, I hope you find a better solution
