IPB2 md5(md5($salt).md5($pass)) issue?
We just wait for an AMD driver fix
Nice info ^^

I know on my win 7 ult 64-bit setup (before i moved to ubuntu), hashcat plus worked fine for ipb2+ multi attack. I think I had the driver installed supplied by the vender disk, but couldn't get a second card installed, and currupted my OS somehow (BSOD on boot even in safe mode). Switched to ubuntu and used latest drivers and everything works except the hash types Atom posted.

I'll guess a workaround is to use an older driver, but i'm not sure which version yet, need to find my win 7 disk to install on my 2nd pc to test.
Ok after dealing with doing 1 hash at a time for the xx11 hash types, i found a work around (tested with vbull, 2711)

Hashcat v0.07 (version i used before updating my machine) works perfect with the latest driver etc.

I confirmed with a mask attack and dict attack via hash type 2711 (i know OP is about 2811).

As i get new hash targets, I'll update what I find.
@hashfixer: I tried a dictionary attack on multi VB hashes and multi IPB hashes. Both were successful.

However, I am interested to know if the hybrid attacks and the combined dictionary attacks worked for you or not?

I get incorrect statistics while cracking multi IPB hashes using a hybrid attack. Even though the hashing speed is good, the GPU usage is high, the time remaining shows over 1 year and also there are no successful cracks.