I have installed the 747 update and have the latest version of FSNavigator. I only use FSN for the map. Since installing the update, FSN takes about 10 seconds to load (the FS9 default 747 loads "instantaneously", for example) but that is not the more serious problem. As soon as the FSN map appears, the PMDG747 makes the "whoop-whoop" sound, the engines reduce power drastically, and there is an FMC message that says "max altitude FL243" -- I've never seen that before. All the MCP lights (VNAV, LNAV, etc.) are on and the aircraft gradually recovers to normal. Switching to FSN again does not cause the effect, only when loading for the first time. I have also had it happen once that when I loaded the flight plan to the FSN map.Any thoughts on the cause and remedy?Thanks.

I removed FSN from my system using the "add/remove software" control panel, maually deleted all remaining FSN folders, and reinstalled FSN 4.7. That seemed to solve the problem.Thanks.