Hi, I have the same module and have encountered the same setup problems.. The ELM327 is supposed to auto-detect the correct OBD protocol for the car, but I have found that some vehicles (mainly ISO, mode3) do not autodetect, so the ELM just responds with "UNABLE TO CONNECT" to all OBD commands.
My workaround was to issue command AT SPA3 at startup which forces the chip into mode 3 and only tries other protocols if mode 3 fails to initialize.
To do the commands, you need a serial terminal program (as a windows user, hyperterm is probably your best bet) set the port to whatever your adapter is connected to and baud rate/protocol to 9600,8n1.
type ATX in the window, you should get a reply "ELMscan 327 v1.4b" or similar, and a prompt. Type 0100. If it responds "UNABLE TO CONNECT" type ATSPA3 and retry. If you get a string of hex starting "41" then it worked. Close the terminal, restart your software.
hope that helps