nobody, that's why it's a good news that you can use the mtgox yubikey for whatever purpose you want. without those unlock keys it was not possible.

Blockchain.info wallet also allows to use yubikey

So far I have found and verified that Kraken.com works with yubikey, I will do some more research today if there are more useful sites that use yubikey 2FA.
And of course, you can configure 2nd slot (the long press) as static password, so anywhere where you need a password, you can use it. It's a random set of either 16 or 32 alphanumeric characters, so it's always more secure than any password you can create and remember yourself. It is of course always the same fixed string (until you reconfigure it again), so it's advisable to add some prefix which you easily remember for each place where you use this fixed password, so that you won't have the same password everywhere where you use it.

Yes, I have just received a reply from support, thank you!

Sorry, I mistyped the number, it's 38699
Basically, I just need to resolve the on hold payment, because I accidentally sent it from my company's account instead of the personal account, I have provided an evidence of that I'm a sole proprietor of the company, so that it might be possible to release the payment and asked if you need anything else.

I've found this topic today when I was thinking about what to do with my old mtgox yubikey and I can confirm it worked for me as well.
I now have a working yubikey, thank you!

I did not have any balance at MtGox so I don't care about losing a potentional access to the restored MtGox (lol)

Thanks. The ticket number is 38669.
The first reply was 7.5 hours and I was already asleep at that time, so I have replied back 5.5 hours ago from now and haven't got any reply yet, so it wasn't 12 hours as I thought, however even at 6 hours it's not very flexible. I can live with longer response for the first reply, but I would expect faster responses after that.

What is an average response time for support tickets at Kraken? I find one support reply every 12-24 hours very slow and when I need several messages to have the issue resolved it really sucks if I need a few days just to resolve a simple thing 

sure, but I haven't submitted anything. I haven't even switched to the X11/X13 port... It was just in the list of pools, but the only pool I used before it went dead was port 3333 (scrypt)...

It looks like their system is banning me for some reason at X11/X13 ports, I have tried another rig with a different IP, when I started it all pools were alive and after a while (without even switching to the X11 or X13 port) I have it both DEAD... Any idea what can be causing this?

I'll ask them, however it would be strange if only X11 and X13 ports were banned for my IP and also just a few seconds ago I saw X11 to be alive and then dead again as I switched to it, which would imply connection problems, but if I had connection problems to the X11 and X13 ports, I would have the same problems for all other ports as well, since it's the same IP address...

well, then I have absolutely no idea what's going on here...
I have also tried to remove the pool and re-add it but it didn't help

I am having some problem with X11 and X13 pools right now. Both X11 (port 3336) and X13 (port 3337) are shown as DEAD in sgminer. All other ports for scrypt, nscrypt and keccak are alive and working.
What could cause this?

yes, now even manual ports 3336 and 3337 are dead for me... very strange. they were alive about one hour ago or so (before I started playing with autoswitch)

hmm. there might be some different problem here right now... I have now switched back from 4xxx pools to 3xxxx and I see X11 and X13 pools are dead (scrypt, scrypt n-factor and keccak are alive). and from what I see, X11 is now the most profitable and that might be the reason why I'm getting all pools dead with autoswitch.

Do X11 and X13 nicehash pools work for anyone right now?

Yes, of course I mean all nicehash pools for different algos. I have set stratum+tcp://stratum.nicehash.com:4333, stratum+tcp://stratum.nicehash.com:4335, stratum+tcp://stratum.nicehash.com:4336, stratum+tcp://stratum.nicehash.com:4337 and stratum+tcp://stratum.nicehash.com:4338 as pools, with no backup because I just wanted to check if it works but it looks like there's no work on neither one of these pools. However when I use same pools with 33xx instead of 43xx, they work. So is it possible that for example stratum+tcp://stratum.nicehash.com:3333 which is a port for scrypt algo works, but 4333 does not work?

I understand that, but there surely IS some work at least for scrypt, since when I go manual, it works. So it's unlikely that there's no work for any algo...

I was just trying to use the auto-switching but it doesn't seem to work for me. When I set pool ports to 33xx, everything works perfectly, I can manually switch pools and all pools work, however when I switch it over to 43xx and start the sgminer, it says that all pools are dead after a while. Any suggestions?

Just to make sure, the latest version that works and includes latest fixes is 0.4.2, right? I wasn't paying much attention for the last few weeks, but I'm still holding my balance so I don't want to lose it :-)

works here...