And just to reply to this, yes, I tweaked it a bit and made it so the frequency of lower level mobs spawning in solo is decreased (which equates to better experience). That also does make it a bit more difficult (but still easily do-able solo, even with really bad gear). Remember, you have exp penalties for fighting things less than your level, and lower level mobs tend to spawn a lot in catacombs, so making them spawn your level more often makes it a lot more consistent.
Just to clarify, in case you want to let others that whined about this know.
(If they didn't already jump off the cliff and sell-out, lol)