It sounds like you have an EFIS-D10A with no remote compass attached. It's very susceptible to magnetic interference from panel instruments.
You have a couple different options here:
- Recalibrate the EFIS-D10A, following the instructions in the EFIS-D10A Installation Guide found here: http://dynonavionics.com/docs/support_documentation.html (page 4-1). You'll want to make sure you have upgraded the software to 4.0 prior to calibrating.
- Purchase an EDC-D10A remote compass from us, which allows you to put the compass sensor out in the wing or any other location with less magnetic interference.
We don't have any official personnel outside the Seattle area, but there are plenty of people who have our products all over; there is likely someone near you with a Dynon product who may be able to help. The firmware updates are actually a fairly straightforward process. All you need is a laptop, a serial cable, and -- if your laptop doesn't have a serial port -- a USB-to-serial converter (we sell these too, although RadioShack has them as well).