Mac Screen Jumping under HDMI ok with RGB

[WayneB]

Just install latest Beta - 1.7 Beta 5 -on 27" iMac running 10.7.2.

Using HDMI Cable, screen on TV Jumps, when connected via RGB it is fine.

Using same Link device works fin with Windows 7 Laptop connected via HDMI.

Jumping only occurs with Mac/HDMI

Let me know if you need a video of the symptom posted.

Please Advise.

[Wim]

Can you tell me what screen resolution you are trying to use and what the make of adapter you have?

Thanks

Wim