Hello Peter,
there are sometimes problems with the enhanced precision in AC9. GS has something changed there in 9. I have a bench, working in 8 and struggles in 9. I know why, but can't fix it. In my case the tube command does not work in this way I used it in 8.
Your object:
The CUTPOLYA is correct. The TUBE too. But working together, they create inconsistence model data. I have worked this out by transfering the parts to a new object, I sent to you. It's very useful, that the poly based commands are very similar. So you can change a CUTPOLYA very fast to a prism_ to see if the coordinates work.
I have replaced the TUBE-command to a block (by PRISM) to get the script run. I think you have created the tube by polyline or profiler. You should give it a try to script it native by the enhanced status codes (1000 e.a.). Then you can adjust it maybe by RESOL or TOLER.
HTH.
Frank