Hi Friends, First of all, I want to say thank you to PMDG for their excellent aircraft. I have the B737NG and B747-400 for FS9; and the B747-400 for FSX. Thay are amongst my favorite flight sim aircraft. The problem I am now having is almost identical to that discussed in a few other posts on ILS tracking with the PMDG B747-400X. But, with enough differences that I felt I should write up this report about it. My apologies for it being so long. I have flown the B747-400X many times in FSX, but this was the first time I've had this, or any problem with it. I do not have this issue with FS9. I recently flew a flight from Atlanta (KATL) to Detriot (KDTW) in the PMDG 744. The date was set to 14 July 2013. I had Active Sky Evolution handle the weather. The flight was without issue until the approach at KDTW. ATC vectored me to RWY 03R. The A/P flew the correct heading (from the FMC) of the RWY center line, but, never lined up down the center. It lined up to the right of the runway, far enough that if I had landed, the airplane it would have been completely off the runway. The CDI needle indicated the tracking status, showing that the localizer was way off to my left. I decided to go missed. On the second attempt I got the same result, and decided to land manually. I figured this was just a onetime hickup, maybe due to a weather issue. I then setup and flew the same 744 from Detroit to San Francisco (KSFO). The date again was 14 July 2013, weather by ASE. Again no issues in flight. Vectored by ATC to RWY 19L. As in Detroit she wouldn't line up down the center of the runway. The CDI, again, showed I was to the right of the localizer. I had to manually fly the approach again. After this I decided to find out if the problem was unique to that livery (NWA) of the B744. So I flew the KATL to KDTW flight again, same time of day, but on 14 June 2013, and ASE weather, in a different livery (DAL). This day ATC vectored me to RWY 21L. I got the same results, only difference is that this time I was left of the localizer, which is what the CDI showed. So I then wondered if this new problem may be unique to the PMDG 747-400X. I reflew the 14 June flight to KDTW, again. Same ASE weather. But, this time in a Level D B767-300 for FSX. This flight was without issue. Again vectored to RWY 21L at KDTW. She intercepted the localizer normally and tracked it right down the center line of the runway to a normal landing. After this I reflew the KDTW-KSFO flight, back to 14 July, same time, same ASE weather. But this time I flew a CLS B747-200. As with the Level D 767, there were no issues. Although, this time I was vectored to RWY 28R instead of 19L; don't understand why. Anyway, she intercepted the localizer and lined up normally. Then, this past weekend, I decided to see if this was unique to the FSX version of the PMDG 744. I reflew the KATL-KDTW flight. Back to 14 June. But this flight I did in FS9, with the FS9 version of the PMDG 744. Used the same time of day. I used Active Sky 6 to handle the weather, this time. This flight went off without any issues. Only, I was vectored to RWY 27L at KDTW (about 8500 feet of runway). But, the airplane intercepted the localizer and tracked it right down the center of the runway to a "text-book" landing. I have downloaded the Flight1 registry cleaner, haven't ran it yet. I thouht I would hold off just a bit to make this report and get any additional ideas from my fellow simmers. Just in case this could be some other issue, perhaps with the PMDG B747-400X. I look forward to reading your replies. As I said earlier, the PMDG B747-400 is one of my farorite planes; my favorite airliner in FS. I want to get her back in the air.