Very strange...works fine here in IE7 using the default joomla and mambo templates... :S
As the workaround may break other templates, I can't apply it as is to next CB.
Could you please try with the default site template of your site, and give feedback here please ?
If it's an issue with only your template, please PM me website url and a username/password so I could take a look at the problem with my CSS tools (webdeveloper extension for firefox is great for this) ?
Thanks