I'm running into the same problems with my DS1511+ and DSM3.2
I followed these instructions to join the domain and set permissions to the DS's shared folders:http://forum.synology.com/wiki/index.ph ... ADS_Domain
Looking at the security permissions of the shared folder using windows explorer, there is only "everybody" as user group listed (with full permissions). Adding new groups to the list fails too.
Mapping the shared folders to the Clients works half way (drives have been mapped, files can be accessed) but downloaded files from the internet for example which have been stored on one of these mapped drives have NO security permissions listed. I can manually set these rights but that's not the point.
I have no idea if this is a common bug or if i'm too stupid (I'm network admin, too btw.).
If you have any hint to get this thing running properly, please tell me.