PRINT TO TAPE Problems - Loss of a/v signal?

Hi all, this is my first post, so forgive me if this issue has been covered previously. I searched and didn't find anything...

I have a MacBook Pro 15", using FCP HD with two 250GB Lacie Porsche external drives. Typically, I've always just output sequences to tape using my Sony GV-D900 clamshell via firewire. Always worked fine, even for long (90 min.) outputs.

This time, I can't seem to get it to work. The NTSC client monitor reveals frequent audio and video "drop-outs" (for lack of a better term). Meaning, monitor goes black or blue for up to 3 seconds, losing all picture and sound, then comes back out of sync. This keeps occurring. Alternatively, I also tried replacing FW cables and even swapped out my clamshell w/ my Panasonic 100a as a record device, monitoring output thru the camera, not the NTSC client monitor. Same thing happened.

However, when *not* using any NTSC to monitor playback and just using the MacBook's screen and my 2nd Apple Cinema display, no drop-out happens.

Eventually, I had to abort and make a DVD instead. That worked fine.

Any thoughts???

Much thanks!

Don B.