I have Studio 9.4.3 Plus only running on windows XP Home without any service packs or any other software to conflict. When I plug my Analogue Video camera in the composite port of my new Dazzle DVC 90 the programme locks requiring me to reboot using the reset button in the front of the pc. If i connect just the sound plug in all is ok only when the vision plug is connected. Any Ideas anyone?

Yes, Get rid of Pinnacle Studio. Its the most unstable editing package I've used.
I used Pinnacle for two years upgrading from 7 through 8 to 9, also had the Pinnacle analogue capture card and break out box.
And every project I did, I would have at least one problem with it crashing or hanging the computer.
The computer was an AMD 3200 processor 2.5gb ram, 1 x 40gb H/D for running Windows 1 x 250gb H/D just for Pinnacle and an external 160gb H/D for transfering files. There was no other software on the computer to conflict it. And every time I contacted pinnacle about the specific problem and why it started hanging AGAIN, I would get the same e-mail which they obviously send to everyone telling me to perform the same old actions everytime.
Sorry for the rant, and trust me I've been there myself and its not nice when you've got a project deadline approaching. But the answer to your question is Pinnacle Studio crashes simply because its Pinnacle studio.
Lets hope that Avid do somthing better than studio 9 for the consumer market when they buy Pinnacle out.
P.S I thought you had to have service pack 1 to run Studio

Rant all you like! I can actually capture with my tv card but suspect i could get better quality with something else
others have suggested that usb capture devices are rubbish and to get a canopus item.
Pinnacle came up with suggestions and one was Service pack which made no difference at all. Will contact Amazon today to return item.