Strange screen issue - white vertical bars on either side
I have a 32GB 3GS and recently upgraded to iOS 4.0 (JB-ed with pwnage tool). Not sure if it's related to the upgrade/JB, or if it's a hardware issue that coincidentally happened at the same time, but my display is showing white vertical bars on either side of the screen, taking up around 10% of my screen. The image itself is "shifted" to the right, which means the rightmost parts of the screen are no longer visible.
I can sometimes get my phone to correct itself by locking/unlocking it (power button) a few times, but it's a hit-and-miss situation.
I've disabled all winterboard themes, and lockinfo too (was initially suspecting either of those), but the issue is still there.
See image for an example: