I went and did the snmpwalk for m0n0wall and saw a couple MiBs that I would like to monitor. One of
them being the uptime.. the problem is, however, when I make my MRTG config it doesn't seem to
work... 

I know this isn't MRTG help, but I've googled everywhere and can't find it.

If anyone has any idea how to get this working I would really appreciate it!

MRTG Config File:
====
workdir: xxxxxxxxxxxxxxx
Target[192.168.1.1_uptime]: .1.3.6.1.2.1.1.3.0&.1.3.6.1.2.1.1.3.0:public@192.168.1.1:
MaxBytes[192.168.1.1_uptime]: 1000
Title[192.168.1.1_uptime]: Uptime for 192.168.1.1 -- m0n0wall.ziekke.net
PageTop[192.168.1.1_uptime]: <H1>Uptime for 192.168.1.1 -- m0n0wall</H1>
====

Error message when running the config file:

====
WARNING: Expected a number but got '2:35:35'
WARNING: Expected a number but got '2:35:35'
ERROR: Target[192.168.1.1_uptime][_IN_] ' $target->[0]{$mode} ' did not eval into defined data
ERROR: Target[192.168.1.1_uptime][_OUT_] ' $target->[0]{$mode} ' did not eval into defined data
WARNING: Skipping Update of 192.168.1.1_uptime, inlast is not defined
WARNING: Skipping Update of 192.168.1.1_uptime, outlast is not defined
====