Mixed Angle Error during simulation

Question

I'm trying to build a mixed-angle project in DVDSP 4.2.0. I've encoded both the main V1 track as VBR with only chapter markers, closed GOP and in Compressor settings made sure the "include chapter markers only" option was checked to prevent any forced I-frames.
When importing the alternate angles into the V2-V9 streams everything goes fine, cell markers are placed both at the beginning and end of the angle and all angles are exactly the same length. However during simulation I get the "Illegal angle situation..." error message. I've gone over settings both from exporting the file from FCP and Compressor - everything checks out according to both the DVDSP4 manual and the Compressor Guide from Brian Gary - can't make heads or tails of it.
Any suggestions greatly appreciated as I'm on deadline.

Answer 1

I had accidentally done two things wrong:
1. I did not send out the main V1 streams from FCP with "DVD Studio Pro" markers, but Chapter Markers instead, and;
2. I manually put a chapter marker at the beginning of the very first chapter. DVDSP4 automatically puts one there called "start".
Now all my mixed angles work perfectly throughout the 2 discs - all 59 of them!
Nothing like finding your own answers!! (^_*)