I see pools saying they get stuck on a block,
I am guessing that they are not really stuck on a block they just have not solved any in awhile and they are just saying they are stuck..
its not like a block gets assigned to a pool and they hash away at it until it is solved... if I understand it correctly, its just bad luck and they have not solved one in awhile.
Yes that's correct they aren't stuck as such, just bad luck and taking a lot longer to find a block which can be caused by low hash rate or bad luck.