Frame Rate Drop after Zoning

I used to run GW on XP with no issues. I've recently upgraded to W7 (32-bit, Home Premium, SP1): now, whenever I load the game or zone into another area, my frame rate drops drastically (in full screen and windowed modes). This is (normally) easily fixed by resizing the window but it's a nuisance. My drive is defragmented and malware free and my graphics drivers are updated (via Windows Update; I'm unsure if it's related but I've been unable to install the official drivers which I understand has been a persistent problem for W7 users). Can anyone help?

Processor: AMD Athlon II X2 250 (3.00 GHz)
Graphics card: NVIDIA GeForce 7300 GT
RAM: 2.00 GB
HD: 320 GB

can you post you memory useage at the time this happens?

Memory use for Gw.exe:

• 85k at character selection screen
• 297-311k on loading into game proper (Maatu Keep)
• 297-317k after resizing window (frame rate restored)
• Gradually falls to 145-153k on exiting to login screen

Any input? :)

Are you using an Aero desktop theme, or just a Basic theme? If you are using a non-Aero desktop, it's maybe sorta kinda possible that the OS is slowing down from switching between 2D and 3D modes.
Other than that it could be the result of some background process.

I switched to a basic theme to see if it made a difference: no change. I keep my active processes to a minimum and have no such problems playing, for instance, WoW or Knights of the Old Republic so I'm stumped.