Just found this, at least with my installation:Symptoms: 1) Engine won't start, but EICAS displays then as running with normal parameters. EGT does not come down from peak at start and then stabilize, just hangs there at peak start temp. Engines are not moving from outside view and do not produce thrust. 2) Flashing red beacon from outside view quits after a few minutes, even with the beacon switch selected to the 'on' position. 3) Gear will not retract after takeoff. 4) IRS's EICAS message 'IRS (1,2,3) on DC', during and after initial alignment.Cause: Dead battery, APU generators on the busses but apparently not charging. Same goes for the engine-driven generators - they do not apparently charge the battery.Cure: Use FSUIPC and check 'infinite battery life=0'PMDG guys, heard of this one yet? My only workaround is to use FSUPIC.....

Yah, ok, sorry. Deal was I purchased the PMDG FSX to get the included unifier for FS9 BEFORE my new computer build. Hence, I had the old FSX 747 installer because at that time I didn't have the juice to run the FSX version. -Dave Ketchum