Firefox (and Thunderbird) are both completely unusable when you move their windows to the external display using either USB to VGA or USB to DVI adapters. The problem occurs using two different USB to VGA/DVI brands, and Mozilla software is the only software the problem occurs with. It's not always crashing, but instead like it can't render itself. You can't resize, maximize, or minimize the windows without them becoming responsive. All other applications work fine. Is there a bug? Are there rendering settings in about:config I can adjust? This is a major issue and I'll probably be forced to use IE or Chrome on these machines if this isn't fixable. I found one other post regarding this from Firefox version 4.0.2, but no solutions or responses to that. Any suggestions or solutions?