green lines flash on my LCD monitor

I hesitate to put this query in the Graphic Cards forum in case folk miss that it might be a monitor issue...

I recently received my new Samsung 226BW to replace my otherwise servicable Acer AL1714 LCD. It plugs in by DVI to a no-name GT7900 GT, a Hong Kong-sourced-via-Ebay card with 512MB. Once the OS and driver have kicked in, it performs excellently. While the system is booting up the screen is plagued with pixel-wide horizontal flashes of green against the black BIOS screen initially and later against the blue Suse boot-up background. After the Nvidia driver starts (with a huge NVIDIA across the screen) the green flashes vanish. They don't appear on the Linux virtual console screens either. Windows, pre-driver, has the same flashes on the Samsung 226BW.

I have plugged the Acer analogue screen into the GT7900 card via a DVI-adapter plug, using the same cable, and no flashes.

Have others seen this behaviour and can anyone tell me why it happens and if anything can be done about it? It's not life-threatening, just annoying and possibly a little worrying.

Thanks,