Strange CGminer problem

[Bru]

I got a webcam and set it up to upload an image when detecting motion to a ftp server on my mining PC. Every time the ftp receives an image, the hashrate drops from 700+ to <100khs and monitor starts blinking very fast (like artifacts) . When I stop the ftp server everything goes back to normal.

Anyone experienced this ? Why do you think is this happening ?

[Jamon]

Which videocards you use?