Boris,
Mitel IP Phones do not connect to the PS-1, only SIP Phones do, so it would not be part of the issue here. Basically, you can see the PS-1 as offsetting a few functions, although this is not totally accurate, such as Database Programming, SIP, and Voicemail. Most likely there was a change to the system manually and it was not saved to the backup database prior to shutting down the system.
Are you having a similar issue or are you just trying to figure out a solution to the problem?
Thanks,
TE