Don't know about the one cell you refer to. Most likely either it or the charger are bad - and if the charger works with other cells, it's a safe bet it's the cell.
One more question: Is using 18650's from laptop battery packs safe?? I have a bunch of them!
It's inherently less safe than using protected cells. Laptop packs have protection built in, but only for the whole pack - once you harvest the cells out of it, those are unprotected.
However, cylindrical LiIon cells are inherently not terribly dangerous. Yes, you can get one to blow if you really
try, but just using an unprotected cell is
very unlikely to give you serious trouble. You can kill the cell by overdischarging it (or overcharging it, but since you're using a LiIon charger I assume that's not a problem), but it'll just stop being useable - it won't blow like a large firecracker.
Should you for some reason decide that it'd be a good idea to connect your car battery to a 18650, however, all bets are off. Even in that case you shouldn't
count on it to grenade, because 18650 cells (possibly others too) have safety terminals that disconnect permanently if
way too much current flows - though I wouldn't bet my life on supercheap ones having this feature.
However, note that LiIons do blow if physically damaged enough - puncturing them, for instance, is a good way to get them to ignite (that'll happen to protected cells too, of course). However, it takes quite some strength to break the metal casing of a 18650.
This is in contrast to unprotected, high-discharge-current LiPo cells for RC use, which are just plastic baggies with no metal protection whatsoever. They are known to blow if you look at them wrong, and there are plenty of videos on the 'tube of people fireballing old, disused or damaged LiPos for fun.
