Invalid digital signature errors

[martym]

Hi,
For the past week, sometime after starting the most current version of URP with several database open, I get an error dialog containing the subject message. I can clear each dialog and I don't see the errors again. However, once I get and clear the dialog, I can no longer drag and drop items into URP. Itmes already in the databases can be accessed, no problem. I am running Window 7 and Office 7. Any ideas? This is a real problem for me as I depend on URP every day. I've attached a snippet of the error dialogs.

Thanks,
Marty