Bad AC3 sound when converting from PS to TS

[Florisel]

Hi everybody,

I am currently writing a tool, which converts program stream to transport stream. The conversion for MPEG2 video programs with MPEG1/2 sound works good, however I am experiencing problems with the streams with AC3 sound. When converted and played back, audio decoder reports missing frames and synwords, which are probably result of some missing or incorrectly packetized audio data. I have spent a lot of time already on this issue but so far I could not find what the problem is and what to ask guru's on this forum for help.
I have uploaded to RapidShare two samples, which I work with:
- one is the original program stream file, which plays correctly
http://rapidshare.com/files/50762719/ZDF_AC3.mpg.html
- one converted transport stream file (from the previously mentioned program stream file), which plays incorrectly
http://rapidshare.com/files/50762888/ZDF_AC3.ts.html

Can someone have a look at these two files and help me to understand what the problem is?

Big thanks in advance.