Ok, so my drive ejected again last night. I checked the log, and very similar thing from before. It has successfully completed several incremental backups but then Time Machine tried to back up, got hung up on a file and disconnected the drive. But here is the wierd thing:
It got hung up on 6 files that were zero (0) kb in size and on a drive that holds my Itunes Media.
Wait, it gets stranger...
At the same time, Itunes was telling me it had an upgrade available. I plugged the drive back in (leaving the Itunes message up) and sure enough, within a few seconds, the drive ejected again. I then selected "updgrade itunes later", replugged in the drive, and so far, everything is fine.
One other thing I noticed in the log is that it keeps referring to a drive by name (D2P2) that no long is on my computer, and in fact was one of the older drives that was causing issues earlier. I checked disk utility and no drives of that name exist. I'm also getting an error message in the log that seems to indicate the drive is trying to re-mount when it has already been mounted.
In the mean time, my internal drives, connected to the docking station, are humming along just fine...