I recently installed two Soundblaster Live! 5.1 cards in my MediaSUV's carputer (the built in soundcard did not have sufficient power to drive the headphones, so my kids kept complaining about low volume). The two new cards works very nicely, except one thing: Now I get what I think is the same problem you were complaining about. When I hibernate the PC while playing, everything goes well. But when it resumes, it won't play. No error messages, it just won't play. It seems to be stuck at the point where it stopped. When I resume I usually hear something that sounds like one sample from the track (almost like dropping the needle on a vinyl record (remember those?) and letting it bounce straight up again, with only that one touch). Is that your resume problem as well? On my carputer this happens to all zones. It's kind of confusing to my kids. I think I'll have to add a command to Girder on resume, to stop the playback and then start playback from the start of the track. Which is exactly what I wanted to avoid! I want it to resume where it stopped just like the CD player in the car. Especially on short stops this annoys the sh*t out of me!
It obviously is linked to either sound card or drivers since that's the only thing I have changed on it. I use the kX Project drivers to get independent zones from each card (two cards because only one of the outputs has the extra strength needed for good headphone sound). Do you have Live! cards, and what drivers are you using?