If you look around here as well as the official DVDFab Forums you'll see this is a known issue. There are many, many users complaining of the same problem. I have sent PM's to both Fengtau and Ting related to the issue. They have agreed it's a problem and have indicated that we should provide patience as they work at a complete rewrite of the BLANK to Mobile, DVD or BluRay module. This is expected over the next couple of weeks. The reply I received from Fengtau is below.
"We are working on brand new a/v sync engine, and it's almost finished, please be patient, since there are lots of work to do."
"We are rewriting DVD to Mobile and File to Mobile to use new Blu-ray to Mobile engine, we are also rewriting new sync engine, and it should be done in one month, please wait for new beta versions, thanks."