Lose sync on output

I've never encountered this problem before with 30 min. programs but I'm outputting a 2 hr. program and am losing sync. I captured my clips in approx. 10 min. chunks and they came in fine. Everything looked and sounded good while editing. On output to the deck I lose sync at around the 45 min. mark. Here's my system setup:

QuickSilver 733 MHz
OS 10.2.6
FCP 3.04
IgniterX 6.01
Igniter RT card w/SDI
QuickTime 6.3

We are going out to a DSR-1500 (SDI) and BetaSX (SDI) using Pesa routers. Any insight would be appreciated.

Kevin

I am having the same problem playing the timeline back to record to a VCR.
I lose sync at about 10 min.
It is on and off. It happens at any time. Sometimes it doesn't happen at all.

G4 533 DP
FCP4
QT 6.3
Igniter RT Component
Igniter X 6.01
OS X.2.6
Medea RTR 720
Atto UL3S