Well, its going to be CSS or JS and CSS combined somewhere down the line. Rip out 50% of your CSS file.... still have the problem?... Get rid of another 50%.... still have the problem? get rid of 50%.... problem is gone? get rid of all the rest and put back the section that had the issue.... still have the issue? ... get rid of 50%. When you have isolated the CSS causing the issue, remove and rewrite it in a way that does not cause the issue.