hi
i brought this up with matrox and they blame apple. apparently nvidia is the way to go. please see the correspondence below:
Hi Sven,

This issue has been brought to our attention and it seems to be a driver issue for the ATI video card in your system. All Mac systems running Nvidia cards have not shown this.

I would recommend that you bring this up directly to Apple as the driver needs to be updated by them directly.

We have seen in some cases where closing the lid actually corrects the issue. Please note that this does not apply in all circumstances.

Best Regards,

Emanuele
Technical Support Representative
Technical Support Hotline: (514) 685-0270
Hours of Operation: Monday to Friday from 9AM to 5PM EST

Please quote all previous messages when sending replies.
Visit our Support Center for the latest News, Drivers, FAQs.
http://www.matrox.com/graphics/en/co...ivers/home.php

From: Noiland Ltd. [mailto:sven@noiland.com]
Sent: Wednesday, September 16, 2009 12:59 PM
To: graph_ts_gen@exch1.matrox.com
Subject: Re: Tech Support - United States - General - Request ID: 20623

hi emanuele
it's a duo-core 2.66 GHZ Intel Mac Pro
graphics card is a radeon x1900, which is a duo-link card.

many thanks,
sven







On 16 Sep 2009, at 12:54, Technical Support wrote:


Hi Sven,

What model Mac system are you using?

What is the model of the video card in this system?

Best Regards,

Emanuele
Technical Support Representative
Technical Support Hotline: (514) 685-0270
Hours of Operation: Monday to Friday from 9AM to 5PM EST

Please quote all previous messages when sending replies.
Visit our Support Center for the latest News, Drivers, FAQs.
http://www.matrox.com/graphics/en/co...ivers/home.php

From: contact@noiland.com [mailto:contact@noiland.com]
Sent: Wednesday, September 16, 2009 12:02 PM
To: graph_ts_gen@exch1.matrox.com
Subject: Tech Support - United States - General - Request ID: 20623
Importance: High


Request Product: TripleHead2Go

Product Serial Number: KFK88855

Product Part Number:

Message: PLEASE INCLUDE THE FOLLOWING INFORMATION: (1) MAKE/MODEL OR MOTHERBOARD - Dual Core Intel Xeon, 2.66 (2) OPERATING SYSTEM - 10.6 (3) MATROX DRIVER PACKAGE - n/a (4) DETAILED EXPLANATION FOR CONTACTING US 3rd dvi out put on THTG has white interference in snow leopard. works fine in leopard.