Slow Shutdown with FireWire connected to External Drive

With the latest version of CPF3 I have been having shutdown in excess of 10mins with FireWire connected normal Reboot 4 mins.
If I switch off the external drive in Shutdown phase it shuts down immediately.

Acer Aspire E700
Vista Home P. Version 6 Build 6000
Intel Core Duo 6300 [ at ] 1.86ghz
1024 DDR 2 Ram
Windows Defender