DVDFAB Beta 8.0.5.3 "Copy" ie: full dvd copy seems to work OK and you can write an .iso file. DvdRip "VOB Passthrough" works pretty good as well in an standard XP bottle, I have been using the latest betas. You can not register DVDFAB , registration will not work. The custom settings configuration page is a little tedious, you must click on the left with your mouse and use the arrow key to move down the custom settings list one entry at a time, click down arrow, click down arrow etc..
I recommend a new bottle each time you try a new beta, as there is less chance of contamination. I use the regular Crossover application installation process , select unsupported application and select a new XP bottle, it only takes a couple minutes and new betas come out once or more a month. If you do get a beta that does not work, just delete the bottle and go back to a version that does work.
I am using Crossover office 9.0.0, on Kubuntu 10.10
on edit: I usually mount the dvd in kubuntu using the "open with file manager" and then close the window, by this time DVDFAB is usually scanning the dvd. When DVDFAB is finished and I select finish I eject the dvd and insert another, as soon as I click on "open with file manager" DVDFAB will see it and start scanning it.
If they ever get it fixed so I can register DVDFAB in linux , I probably will as it is a good program.
DVDFAB beta information: