Software :: DVD Authoring / Compatibility?

I would like to know if anybody can help me with a very frustrating situation in which I find one of my video productions: after producing a YOGA video and going through a very happy production and postproduction period, we decided to Author ourselves a DVD for replication and this is what happened: after editing in final cut I compressed with compressor then went into DVD studio pro 4 and did the authoring following all the steps that we learned with the video tutorial of Larry Jordan which basically recommends to use Roxio toast for the final burning, everything looked good and chapters and extra audios, menus seemed to be well done, then we went into the testing for compatibility issues and we found that we could not play the DVD either in PC nor in 90% of the DVD players, but we could see it with no problem in any macintosh available to us, amazed of the outcome we send the DVD disc to the replicating company for their diagnosis and they told us that we had a problem with compatibility and that they need to re-author almost everything with a cost that we did not have in our budget. I decided to try not making the final burning with Roxio and did it with DVD studio 4 and the same thing happened, for a while we thought that we did something wrong in the process and we repeated several times with the same outcome, I suspect it has something to do with deciding which regions to make it ( we always choose all the available and we left unchecked the section for anticopy and macrovision because we thought that the replication business needed to apply that part. Tried to get some info from them and we only got more confusion, they told nothing about the anticopy issue and the only answer they gave us as the possible cause of the problem was that is a problem related to Mac G5 of recent production that they produced DVD only compatible with Mac computers which seems to me a very surrealistic answer difficult to believe�finally I am in a situation in which I am delaying my clients video and cannot tell why and also we made an investment in software in order to give authoring services to our clients that I can�t use or offer anymore... And the replicating company is telling me that they cannot really tell me what the problem is so I can solve it and just pay for the replication but they can solve it for me paying an extra cost.