Not DVD overburning, that seems to be a big fat zero at the moment...
The one above, Enable overburn Disc-at-Once burning
If you have only 90 mininute CD-R (stated as 90 minute, or in some cases, just "80 plus"), then set the limit to 89:59:74 (actually, not that critical, you can set it higher, but it's better to set it according to the "long" media you do use, to avoid failed attempts - though you might be able to scrapa an extra minute, if you use Nero 6.6.x.x and the 30 sec leadout option)
On the "General" tab, you should also place the yellow and red markers at useful points - the default being 74 and 80 (for 74 and 80 min CD) if you use 80 and 90 min medi, those would be the obvious marker points to use, so you can see immediately that it needs a 90, or is too big for one.
Since >80 media is made that way, and requires overburn to reach capacity, it's not risky on any drive that is known to have acceptable overburn support.
The Liteon's have always been overburn capable.
Theoretically, if you overburn ordinary media:
1. You push the drive mechanism beyond normal travel, it could jam a badly designed drive.
2. If you burn-off (as you would if you had an 80 in there, when you thought it was a 90), then the drive runs out of tracking - it should be able to handle that, as it could be presented with faulty media.
The biggest hazard, is actually presenting an overburned (ordinary) CD with no/minimal leadout to some READERS, as they are much more likely to react badly to slipping off the end of the leadout. The "short leadout" of 30 seconds (or failing at more than 1/3 into a normal leadout) is about the least you should trust.
PS. Some drives don't READ 90 and 99 minute media well, even some drives that can WRITE them!