Last time after a lot of trial and error I managed to get it to work as a repeater (non WDS). It was bloody unstable, so I ditched it. Can't remember the DDWRT version though.
Here's one of the guides:
http://www.dd-wrt.com/phpBB2/viewtopic.php?p=604628

I'm running on the same version, same router, but after following KL Seet's setup guide, it seems router in unable to connect via WAN interface. Unable to connect to PPPoE. It seems the WAN port is disabled or so.. Username and password is correct, setup follow exactly the same as KL Seet's guide....  

I think i found the link with solution here: https://dev.openwrt.org/ticket/11898

Paste it here to help others with the same problem.

I bricked my router while trying to flash it back to original F/W to test the WAN port.

It behaves like a christmas tree now.

Power - LED ON
Initially - SYS, WLAN, USB, QSS - Flash once
Then - LAN 1 - 4, WAN - Flash once
(Then the cycle repeats)

Any luck with un-bricking my router??