TBC when it writes the PRO file uses a Seed TMODEL.PRO file that has this setting control. If you have a Job that goes beyond the setting in the PRO file you will get this affect, and that setting is not accessible anywhere in SCS900 - what you need to do is change the TMODEL.PRO file in a folder location that TBC looks for, that has a larger setting predefined. I created a number of those and posted them on TBC a while back with instructions on where to place the files etc. You will need to rewrite the PRO file with the new seed file to rectify the problem. Alternatively if you have a license of Terramodel (even the free basic version which can I think be downloaded from Trimble.com) you can go in and change the setting yourself - the instructions are in the post I made previously.
Click Here for the link I made earlier
Alan