Yes, Apple made some changes in QT 7.3 that screwed up our recording into QT Pro.

There is a workaround. You need at least two of our Camera emulation apps to make it work.
This can include the free Qamera.app on our web site.

1. Quit from QuickTime Player Pro.

2. Open the Package for Qamera.app, and copy the driver
QameraXXX.component to /Library/QuickTime.

3. Do the same thing for DotMatrix.app, copy
DotMatrixXXX.component to /Library/QuickTime.

4. Start Qamera or DotMatrix and enable Rebroadcasting.

5. Open QuickTime Player Pro.

6. In the Preferences, Select the DotMatrix (or Q@mera) driver as the Video input.

We know for sure that QT 7.3 is no longer recognizing the unix symbolic link to our driver. This is compounded by the fact that the new Leopard capture APIs have problems when there is exactly 1+1 camera drivers installed in the system.