This may be a bug missed during testing:On the ground I like to increase my sim rate (sometimes to 128x) to hurry up the IRS alignment time. I know this can be changed in the PMDG menu but I like doing it this way sometimes. When reducing the rate to 1x after a few seconds I get several warnings:"AVNCS FAN OVRD""CABIN PRES RELIED""CABIN RATE""OPEN OUTFLO VALVE"For some reason, during the increased sim rate the aircraft has sensed a dramatic climb and the cabin alt sores to 50,000 very quickly then starts back at -9,000. This cycles over and over every minute or so. The A/C doors are open and the outflow valve IS open. FS9.1 Windows XP.This isn't a biggie, I'll just stop using the sim rate to decrease alignment time. :( Alexander GuntherLos Angeles, CA

This may be a bug missed during testing:On the ground I like to increase my sim rate (sometimes to 128x) to hurry up the IRS alignment time. I know this can be changed in the PMDG menu but I like doing it this way sometimes. When reducing the rate to 1x after a few seconds I get several warnings:"AVNCS FAN OVRD""CABIN PRES RELIED""CABIN RATE""OPEN OUTFLO VALVE"For some reason, during the increased sim rate the aircraft has sensed a dramatic climb and the cabin alt sores to 50,000 very quickly then starts back at -9,000. This cycles over and over every minute or so. The A/C doors are open and the outflow valve IS open. FS9.1 Windows XP.This isn't a biggie, I'll just stop using the sim rate to decrease alignment time. :( Alexander GuntherLos Angeles, CA

I don't think PMDG products are approved for more than 4 or 8X. You are probably screwing up the code by going past the allowed speed. Just use the faster IRS align time, that's what it's for.