I’ve stayed in D’Ma hotel once in Bangkok – btw a good value for money and also located well, so I don’t doubt about their blacklist, they will have good reasons to publish this.

I’ve never booked via asiarooms, but this year I used to print their internet rates for negotiating walk in rates in some hotels in Bali any usually it worked just fine.
I knew already where we indented to stay, so I walk just into the door asked for a room (mostly 4 days or so) had a look in the rooms and then asked for the price, by presenting the internet rates from asiarooms most of the hotels accepted the price.

The situation was a bit different in Candidasa Beach cottages, the staff at the reception was clueless, when I asked for the manager he got almost furious and claimed, that he wouldn’t have any contract with asiarooms at all, after some discussions he gave me a better price (thought not the promoted price by asiarooms), gee the guy was really angry, not very common for Bali and he demanded I had to pay in advance (which was of course no problem).