SF4 costume pack not working - HELP!

ok so my PS3 is PAL - Australia (region 4) and my version of SF4 is NTSC (region 3) from Hong Kong.

I just bought the costume pack and downloaded it but it doesnt work. My friend has the PAL version of SF4 and he bought and downloaded the pack as i did but his worked.

I just wanted to ask, the DLC from AUS PSN only work for region 4 games right?

Yeah, your sf4 need to be region 4 version. DLCs are region-locked.
The same thing happened to me in Killzone 2. I bought DLC from PSN US but the game was EU version so they didn’t work.