Altitude Question

When setting up my Wilco 737 PIC, I notice in the lower right corner of my EADI, below the DH, the number "-2" appears. Is this normal? Once I take off it goes away and doesn't come back until I land. Is there something I should be setting prior to take-off? This happens at all the airports. My aircraft isn't sinking into the ground and doesn't appear to have any problems taxing or landing. I've read the manual and can't find anything about it. I've posted this question on the PIC website, but AVSIM gets a lot more visitors.If anyone has experienced this, please let me know what I can do to make read zero or higher. I know it has to do with the altitude, but why is it showing -2?Thanks,Mike Franks