Question for Tech Support...

I am preparing to transition a single server Exchange 2003 organization over to a single server Exchange 2007 organization and have three questions.
1. Is POPGrabber Pro compatible ?
2. Can I use two installations of POPGrabber Pro temporarily while I move mailboxes from one server to the other.
The current exchange 2003 server uses a licensed version(1.0.1.264) of POPGrabber Pro to get all internet mail from a hosting company.
I would like to transition gradually to minimize disruptions should any problems arise and in doing so I figure I would need two installs of POPGrabber unless you have a
version that supports multiple servers.
3. Can I reinstall the Pro version that I already purchased for this temporary transition without needing to purchase again ?