MPT & V400 Trouble

I have installed MPT v3.11h.
When I connect my phone with the USB cable and open the app it seems
to find my phone. Info shows the above version of MPT and Motorola CE
V400.
When I try to look at the contents of my phone or transfer data from
my PC with Mobile Explorer after the initial startup phase the 2
transfer icons between the My Computer and Mobile Phone windows become
grayed out.
If I go to Melody Studio and try to transfer a file tp my phone I get
a box that reads "Transfer in Progress: Sending "file" to Motorola
Comp Modem". After about 1 minute I receive an error, "Unable to
communicate with mobile."
An attempt with Image Studio gives: "Transfer in Progress:"file" to
Motorola Comp Modem". After about 1 minute I get "The image transfer
has failed."
The modem shows in control panel and a query seems to show all is
well.
When I attempt to use live update nothing seems to happen and the
version doesn't change.

Can anyone help?
Thanks.
Shagnasty