Image corrupt or truncated

[boulder606]

I am using 4.1.12.

In firefox I am getting on images the error: Image corrupt or truncated. Mostly when I load a gallery of a say 10 images but the images not as large around 150kb.

When I switch to apache all works fine. No errors. Strangely this only happens in FF. So after long testing here are teh results:

error happens only on FF in combination with litespeed.
FF in combination with apache works fine

All other browser with litespeed or apache work fine.

I am using PHP 5.3.10 and tried all option like force update recompile php. No luck

Thanks