Defrag the hard disk that contains FSX.
I just did 3 back-to-back COMPLETE/Name defrags using O&O.. still takes 1min 25sec to start up.. but I do have a lot of aircraft and paints on there, so no wonder.
Mine takes a while to start as well, but only the very first time.
If I close (quit) the sim, and reopen it, it starts in exactely 7 seconds
The DisablePreload is in my FSX.cfg as well.
Mine does the same thing (except I don't know about the 7 sec thing