well its not guaging properly, first see if you have a ground bolt.
http://www.cetmerifles.com/forum/vb/showthread.php?t=7872
if you do, that needs to be changed out for an un-ground bolt. then you need to re-check the bolt gap, but if they ground the bolt its because it wasnt guaging correctly. so then you go up a size in rollers
heres how to get the bolt apart for roller swapping
http://www.cetmerifles.com/forum/vb/showthread.php?t=6278&highlight=bolt+disassembly
POF usa has the rollers, get +2 and +4's (yes they are for HK's, but they are exactly the same as what is in your CETME) and yes I would get both sizes, if you get your rifle working 100% even if you don;t initially use the +4 rollers, they'll just be on hand to install as your rifle wears...
if after all that it still does not have the correct bolt gap, something else in there is worn out and it will require the attention of a smith, thats where I am at right now, although you could do the work yourself it will take a fair bit of cash just for the barrel press, if you choose to go this route, theres plenty of info on cetmerifles and plenty of people to help you out.
I'm going to contact the smiths recommended in the thread I posted.
p.s. Kudos for actually checking the bolt gap before firing it, most people don't.