Is there a way to completely reset / regenerate Quick Look preferences (system-wide)? Quick Look fails to work on many file types that actually have Quick Look plugins and I fear that some file clobbering has occurred during my last two OS upgrades.  

When Quick Look fails, the Quick Look preview is a blank page with:

foo&lt;TITLE&gt;&lt;/HEAD....  

Has anyone else run into this issue?
From the CLI

qlmanage -r will reset the Quick Look cache.