white bar in rivatuner

[john34]

I got a new geforce 8800GS and when i do detect now it detects the clocks but the memory, it looks like there is a limit because i see a white line in the near of the bar. when i go over that white line there is a mark like this ! on the memory picture. what does it mean? it means i cant overclock beyond the limitation where the white line is???