Sonos system locks up iMac

Question

I saw an earlier post (2009) from a user who felt his Sonos music  sharing system was locking up his iMac.  I have an iMac that is about a year old.  I purchased about the most sophisticated system available.  I have the 27" screen, the 3.4 GHz Intel Core i7 processor, 16 GB 1600 MHz DDR3 memory.  I also have a fairly robust Sonos system--5 zones.  I use a NetGear wireless home internet with both 2.4 and 5.0 GHz bands.  I have a large house so I am using a NetGear repeater to broadcast the wireless signal to my upper floor.  With all this in place, with about 75% reoccurrence, when I attempt to play music from the iTunes files on my computer (this problem does not occur when I simply try to stream internet Radio such as Pandora), I get a Sonos error that the music file is not properly encrypted.  I have spent hours on the phone with Sonos help to  resolve this problem, but I am beginning to conclude that this is not a Sonos problem.  In fact, most of the diagnostics that I have conducted on my Sonos system indicate that the Sonos system is working properly.  The problem seems to isolate to a problem either with my wireless internet (my Sonos  system is not hard wired into my computer and has to connect to my computer via my wireless internet) or my computer.  I am beginning to conclude that this is a problem with my computer or the interface between my computer and Sonos.  I have already turned off my computer "Sleep" timer to eliminate this as a problem.  What I have noticed recently is that when I have these problems playing music through my Sonos system, is that my computer overall is locked up.  Any application or file that I attempt to access, results only in a "spinning wheel" and a notice that the application is not responding.  I have attempted to monitor what is going on with my CPU during these events using the Activity Monitor and whereas I usually find that I am using less than 5% of my CPU's processing capacity, Activity Monitor tells me that I am using over 50% of my CPU capacity (and sometime 80% or more) and the big culprit appears to be the "smdb" process.  I am not a techie and have no idea what this is.  But what appears to be happening is that for some reason, my CPU's processing capacity appears to be eaten up and just about everything on the computer ceases to function.  I have scanned my computer for viruses (I use Intego Virus Barrier and Net Barrier to try to keep my computer clean) and nothing is picked up.  I recently had a hard wire problem with this computer (it wouldn't even turn on) and I took it to the local Apple dealer and they replaced the power pack and the motherboard.  Recently when this problem ratchets up, I cannot even get the computer to shut down and I have had to resort to pulling the plug.
Does anyone have any ideas?  I am becoming very frustrated with this problem and am even considering returning to the PC world.

Answer 1

Plague,
Are you running XP Service Pack or 2? There were some problems with SFMAN32.DLL that were corrected with SP2. Also you may want to clean boot into the system when installing the driver update. This is described at the end of the FAQ at the top of this board.
Jeremy