Matrox G400 and multiple rendering contexts. Help!

Presently I have to keep my rendering contexts in child windows that reside over a GDI drawn background. I am using a Matrox G400 dual head graphics card running a single application that stretches across both displays. I can create a rendering context in one child window and use it without incident. However, if I create multiple child windows and create seperate RCs for each, using the same pixel format, they will both display initially, but the rendering context itself seems to discontinue after I do anything that would force a screen redraw; aka sending a WM_PAINT message, alt+tabing, or forcing screen redraw. I have gotten this same code to work flawlessly in all hardware accelerated pixel formats on all of our other cards. I have tried enumerating through all the pixel formats for the G400 without positive result. I have tried every driver I can get my hands on, including the one put out on Monday.

Thank you for your response in advance!

[This message has been edited by JJohnson (edited 11-10-2000).]