UCCNC & Stepcraft 300 problem

I have recently bought the Stepcraft v2 300 with the parallel port adapter and the uc100 motion controller. I'm trying to do my first CNC milling, but I have a problem. Whenever I try to jog the machine to the right on the X-axis, I get an error in UCCNC saying "A machine axis position software limit was reached. This axis was now stopped." I'm using the V2-300 profile from the CD.
On a related note: when I load the included test file ("Stepcraft-Logo.nc"), no matter where I zero the machine, I always get the error: "The current job is out of the set software limits. Adjust the softlimits to fit the job extents or disable the softlimits."
In the configuration tab the softlimits are set to 0 (-) and 207 (+). Altering these does not seem to have any effect.
After installation everything seemed to run fine in a test run, but now I can't figure out how to make it work anymore.
Any help would be greatly appreciated.

Thanks in advance!
René