I finally got iGuidance 4 to work with wine using a USB GPS receiver (old DeLorme unit). I never got it to work before (version 3 or 4) because it would never detect the GPS unit; it was due to a regression in the serial dll used by wine starting with wine 0.9.23, and only affected some USB devices, depending on the feature set of their kernel driver.

The fix for it is modifying a couple of lines of code in dlls/ntdll/serial.c to ignore missing kernel features for certain devices. Please see here: http://bugs.winehq.org/show_bug.cgi?id=8783#c46 for the fix. Thanks!