True Vertical Depth Curve problems

[kat]

I am having an issue plotting a True Vertical Depth Curve. I have gamma ray data from a deviated well and wish to depth correct the data to vertical. I have created an Orientation tab and have the deviation survey entered. I understand how to use a scale bar in the design template to reflect the true vertical depth down, but I want to depth correct the actual gamma ray curve to vertical. According to the help menu I can do this by ticking the "True Vertical Depth Curve" box in the Curve Column setup (and choosing Dip from Vertical, my orientation data type).

However, when I check this box the data will not plot and I get an empty curve column. If I uncheck the box, the data plots fine. I've been through the deviation survey numbers and can't figure out why the program won't use the survey to depth-correct my curve.

Help!

Any suggestions?