The FS2002 gps.gau gauge is incompatible with the FS2004 GPS gauge. This is the only thing that prevents these planes from flying in FS2004. It is easy to correct this problem.
Go to any aircraft in FS2004 that uses the native (for FS2004) GPS and find its panel.cfg file. Open this example file in Notepad and find the place where this gauge is specified. You are looking for the exact form of the GPS in the reference but do not worry about the numbers after the gauges name (these are just size and location numbers). Write down or highlight/copy the GPS gauges name before the first comma but not the following numbers.
Now open the panel.cfg file in Notepad for one of the CT2K aircraft and go find the reference that says "gps500x!gau". Remove this reference name but not the comma or the numbers following the first comma. Either type in the name or paste the name you obtained from the native FS2004 GPS in the place of the old FS2002 gauge. Do not to forget to save the altered new panel.cfg file in the same spot you got it from the CT2K aircraft. That is it. Go fly in FS2004.
