There is a helpful page on how to exchange files between PC and iPad. However, in the case of CustomData I cannot make it work. The instrcutions say to drag the CustomData folder to the app shared files but this does not work (no entry sign stays on). You can transfer the actual file but it goes into the file list and not the CustomData folder. Looking things up on apple support it seems to say you cannot tranfer folders and only files. Because you can't place it in the CustomData folder, SD does not see the information even if you restart.

Maybe it's worth checking you've got the latest version of iTunes. The steps I mentioned above are how we've been testing this ourselves with iTunes running on a Mac.

When I first tried I only had latest version of iTunes. I have updated iPad to 5.1.1 and have latest SD. The only difference would seems i am using a windows PC. Searching seems to still say you can't copy folders with itunes file sharing so may be it is a windows thing?