Did you try merging any new trunk changes into your branch (forward integration) before attempting your reverse integration (branch merging into trunk)?
Do your web browsing with Firefox, have Windows XP Firewall running, perform regular virus/spyware scans of your PC, don't run/install email attachments.
Ideally go out and purchase yourself a router and use that as your gateway to your broadband connection rather that directly having your PC connected.
Yeah, I've had similar issues, especially when changing from the 3rd party layout managers to the built-in Java platform mananagers (GridBagLayout etc).
The GUI designer still has some issues, but in it's current form, I find it very useful. [ February 06, 2006: Message edited by: James Swan ]