I am seeing and issue that is specific to SharePoint 2010 and Internet Explorer 10.
In this configuration, if I try to use the book icon of the Assigned To field to select people, I am getting an error. If I just type the names in the field, everything works fine.
I have been able to replicate the error on 3 different, unrelated environments, so I assume this is a Microsoft bug.
Is there a fix for this?