I installed MRTG and that went fine, and it was running for a while. But than I saw the clock was fast by 24 hours so I set back the time. MRTG stopped updating and i figured because I had set the clock back 1 day, it would take a day and than start back up.

It hasnt. First I tried:

/etc/rc.d/init.d/mrtg start

but it says MRTG is already running. Running:

/etc/rc.d/init.d/mrtg stop

fails. What should I do?

(this is why I am a hardware guy)

Never mind, I was overlooking the obvious.

stupidity++

What were you overlooking?
Im having the same problem.
However mines just stopped working.