Ripping Multiple CDs simultaneously

Has anyone had experience with this:

Wife has about 900 CDs. I started ripping them into WMP11. On one PC it was
going to take forever so I began using other PCs with WMP11 on our home
network. Two laptops and two desktops ripping simultaneously to one rip
directory on an external USB hard drive attached to one of the desktops.
Using four PCs at once really helped to speed the ripping process.
When I got done three days later I noticed that some of the albums had
dropped tracks and some albums had extra unknown tracks added. The error rate
was about one bad track (mostly missing tracks) for 70 good ones (about 10%).
It could be higher I just looked through the song list and noted the missing
tracks I could see. So far there are no other issues like sound quality or
anything else with the tracks that came through.
I figure the problem might be that piping all that data into one drive
across the network might have caused some data collisions. I could probably
work around it by saving to local drives first then manually moving the files
over later. Then maybe someone knows a better way.
It would also be nice if WMP could check the rip tracks with the online
database and retry ripping tracks that didn't make it. Maybe WMP12? Maybe I'm
just dizzy from feeding in CDs.
Any comment or suggestions would be welcome.