I agree with most of the above. Myself, I have a much harder time on Ku than on C-band. Only reason I can think is that the LNBFs I'm using on Ku are lower quality than the LNBs I use on the BUD.
However, the reason for response is that since the OP'er is using an Azbox, I wanted to make sure that the problem wasn't one of technique. Ie with my Elite, generally I have to have all the parameters correct or it won't lock, including both FEC and pilot on/off. When you go into the Azbox, and set up the parameters, generally the signal/quality meter doesn't function. So what I do, is just go into the transponder edit screen, and set up the transponder with DVB-S2 parameters, THEN, I exit that menu, THEN, I go back into that transponder I just created, and one by one step through all the FEC values on both pilot on and pilot off. Generally I'll hit on the proper parameters. Most of the time, when you get DVB-S2 transponder parameters from a list, they don't tell you all the parameters, particularly the pilot, so you have to experiment, however with the Azbox, you can't experiment until after you have created the transponder, exited that page, and gone back into edit again.
At least that is the way MY Azbox behaves. There is a guy over at Satforums, who swears up and down that you absolutely cannot do what I do. Ie he says that with his Azbox, once you create the transponder, that you cannot edit it to change to the proper parameters. I am really confused as to why his Azbox would be so different from mine.
Anyway, that's the technique I've used, and I've been able to lock 90% of the S2 signals I've seen listed. I generally cannot lock the Ku NBC on AMC1, however, due to the 26 deg skew offset with my 3' dish, and the fact that my BUD has too many dents and is too warped to work well on Ku. But most other sats work OK.
One other thing re Azbox and S2. If you get a lock with 7/8 FEC, that is the wrong FEC. It shouldn't be in the S2 menu, and you get confused results sometimes.