I just came back from the visa office and no problems...the lady didn't ask any questions after seeing I was applying for a one year multi-entry visa. She just asked to see my hkid card and asked for a copy of it, then everything is done!
Besides, it only costs HK$600 for a one year multi-entry visa(would've been $400 for a 6 month one). But I did have to queue up for 30 minutes...
We'll be going to Shenzhen for lunch & dinner next weekend for sure