Tell me about it.
Went to the customer site to hop extensions to working voice mail box extensions, was asked if I could change the hold and transfer recall times (I had defaulted the system which "corrected" the original SVMi issue, so timers were at default values - often not long enough for most of our customers). Sure. Until I look for them - they weren't there. *No* recall timers (hold, transfer) were there, in system, trunk or station timers. MMC 315 was missing also (was going to talk the customer through a set relocation over the phone to save the 2 hour round trip time), "Invalid Data" was the response when it was attempted. Having almost as many problems with this as the 616s (at least I can make this limp along for now, the 616 just fails).
Sad part is they were all working great until about the last 6 months (except one, it never really worked right, replaced it 18 months ago with a 100, not a problem since), making the installations between 4 and 7 years old. Upgrading is good, they can still use their existing keysets.