First, what tools and procedures did you use to get to the point of the "backup GPT table is corrupt" message, and is that error message reproducible by reproducing those steps? It could be that you did something wrong in creating the partitions, and that this is causing problems, but without knowing how you created the partition table and filesystems, that's impossible to know for sure.
Second, if the error is reproducible and if you're using common partitioning tools (such as Disk Utility in OS X, GParted or gdisk in Linux, etc.), then it's very unlikely that you'd get a consistent and reproducible problem in the partition table. This makes me think that you may have a defective USB flash drive on your hands. I can't be sure of that, though, particularly if you used some oddball tool to create the partitions.
Third, if a partition (such as /dev/sdb2) is inaccessible, you may need to use filesystem repair tools such as fsck on it. Further diagnosis would require knowledge of what filesystem it is (I'd guess HFS+, if you intend to put OS X on it). The output of sudo fsck /dev/sdb2 and/or sudo blkid /dev/sdb2 would be useful in further diagnosis.
Fourth, if you're trying to create a bootable OS X disk, you should probably be doing this in OS X, not in Linux. Is there some reason you're trying to use Linux for this task?
I recommend you edit your question to provide all this additional information; it's too much to fit in comments.
