Video Capture of CELX script Not Syncing

[Thailandian]

Greetings fellow Celestia lovers.

Background (skip if you like): I am a noob when it comes to Celestia scripting, but I'm reasonably familiar with Celestia, and very conversant with other scripting languages - especially javascript, so the syntax and OOP side of things are not a problem for me. Getting my head around the Celestia specific stuff such as frames and vectors is more of a challenge.

Now my problem ...
I'm using Celestia to make the background for a music video. The foreground will be a combination of Blender 3D animation and green-screen live action. So it's important that the video capture from celestia be frame-accurate.

I started with .cel scripting, and while the results were stunning, I was a bit frustrated trying to get all that I wanted, so spent several hours today, learning Lua, and converting my .cel script to .celx.

But when I tried capturing my new script, I found that it did not sync properly with the capture function. It was as if the script was proceeding in real time, not waiting for each frame to be produced before advancing.

I checked capturing my .cel script again, and Celestia faithfully produced what I had scripted.

I don't expect to capture anywhere near real time. In fact it took well over an hour to capture less than two minutes of video that I had planned in my .cel script. I don't mind that if I get a good result.

So my question is: Is it possible to capture a frame-accurate video of a .celx script, or do I need to go back to .cel?

Thanks in advance for any advice.