editing FCP 6.0.6 Hidef XDCAM footage (1080i60) mixed with prores graphics footage (NOT HQ)(1080i60) and Canon t2i b-roll (not sure what the codec is but it is full raster though 1080p30)
This product can work beautifully, wonderfully etc - however, when I go to master my sequence (export to xdcam disk) no matter to which kind of footage L&L is applied (XDCAM or canon t2i) the video evidences flash frames and extreme scale variations. Oddly, it will play back fine in FCP but when I export it to another video device is when it starts doing this.
I suspect there could be issues with the T2i footage. I have the same camera (550D here in Australia) and if I work with the footage natively in FCP (v7) I will eventually see memory errors. This could then affect rendering or output in the XDCAM footage. Perhaps try restarting, then using L&L without the T2i footage in a sequence and see if the same problems recur?
You could also try exporting your sequence to a ProRes QuickTime movie first, ensuring that's problem-free, then transferring that back to your XDCAM disk.
Regardless, some CoreMelt engineers may be able to provide more assistance, and I'll let them jump in here if they can.