Here is my take on that error message- but my opinion is not the final say and others should chime in here.

I have seen it sometimes with uploads and the processor works fine afterwards so I choose to ignore it. I have also seen it be a real problem. If it turns into a problem the best way to resolve it is to "retype". I forget the exact procedure- but its in your owners manual. Basically you are telling the processor to reload a factory preset. This WILL ERASE your info so the thing to do is make sure your MSF file is upto date- do not fetch otherwise youll lose MRC info. Just look at settings and move over by hand. When you retype the instructions will tell you to hold an u arrow- they really mean the up volume button- I stood there for what felt like hours holding the up arrow button feeling like an idiot. Press the up volume button. Once you have done this- load the new firm ware again- it should load with no error messages. Then you deploy your settings, etc. A little PITA but worth it IMHO.

btw- heres what M says about their firmware:

Quote
861 Product Firmware Release 4.25 (2007-02-07)

New Features
RS232. "SO" emulates the source key.
DSP. Automatically applies filtering for Meridian passive inwall and onwall speakers to optimise their bass response (requires latest configuration program).

Software Fixes - Critical - Software must be updated
None


Software Fixes - Useful - May be useful to upgrade but not essential
Bass. Large analogue speakers and subwoofers had reduced bass levels with v4.24. This is now fixed.

Software Fixes - Minor - Update probably not necessary
RS232. Faster response to repeated RS232 commands from home automation systems.
RS232. Extended lipsync range (0ms to 85ms) now available with APxxnn as per other menus; xx is "4C", nn is "00" to "AA".
from:
http://www.Meridian-audio.com/download/components.html

click on 861 v 4.25

Thanks to the Mothership smile

best regards,
Jerry

Best regards,
Jerry
Main System: 861v6, DSP8000s in corners, DSP7000s Center and Sides, 1-9 humans.