Micrologix 1500 Output O:0/0 Wont Work

I am using the HSC feature. Seems to work fine. But, Output O:0/0 wont engerize. Shows that is should, all others work fine, Can force O:0/0 on and it works.
Must be something in the Function file for that HSC, darned if I can figure it out.
Don't see how to disable the OMB output mask.

Sure could use some advice.

Post your .RSS file and someone can take a look. ( zip it first, then post)

I changed the OMB value to a negative value -1 and still not luck, then changed it back to "0" (which it was to begin with) and now it works.
Don't understand why this was, but it works now.