N113AR

When looking at the past flights for N113AR, some are filed as a GLF4, although others have it as a GLF2. Are there two different planes with close tail numbers that might get mixed up in the filing process or is it something else? According to airliners.net, there are pictures of N113AR and they are of a GLF2, but I found another page that said the registration info and it had it as a 1987 G4.
Just a little confusion and I was wondering if anyone could help me sort it out.

Thanks

http://flightaware.com/live/flight/N113AR/history

This is A-Rod’s plane and has been discussed here before. He upgraded to a G-IV last year. I saw the G-II pick him up in Seattle in May.

It’s probably just an error when it shows up as a G-II now. Either the pilot or person filing the flight plan also frequently files for a G-II or its saved in their computer.