I also own a DW822A BenQ drive. I have had it for about 5 days. On the SUBJECT of BOOKTYPE. You set it once with the BenQ Utility. The DW822A and BookType set to DVD-ROM works perfectly with NERO. You MUST have the lastest version of V6 installed for this to happen. I was having problems as you described until I found the answer on the 2500A forum to upgrade to the latest NERO.
I love this drive. Over the past 1-2 months I have used all of the following drives. I would rate NEC #2 with the modded firmware.
LiteOn 811S - non-modded
LiteOn 851S - modded
NEC 2500A - modded
Pioneer 107d - modded
The BenQ generates super result with K-Probe. NEC #2, Pioneer #3 (#1 for -R media), and LiteOn just OK (so so) on burns.