I logged into Salesforce.com this morning on IE7 and can't see any buttons to actually execute any commands. The Release Candidates have been out for quite some time on Internet Explorer 7… there's no excuse that an On Demand/Software as a Service provider was not prepared for this.
Even worse is the dumb message in their support. They recommend that you DO NOT immediately upgrade to IE7 when it becomes an Automatic Update. Ummmm, if it's an AUTOMATIC update… how do you NOT immediately upgrade? Oy.
CORRECTION: If you clear your cache, it will work.