First of all, a hat tip to mandrews for his suggestion.
I have an old, noisy wd raptor drive I was using for my temp folder and the constant writes were driving me crazy. I was also already using Dataram cache for my temp internet files so I decided to give mandrews tip a try. It works, but it requires supervision and tweaking.
To begin with, Dataram cache's default setting is FAT32, which means a junction or symlink, which needs NTFS, wouldn't work for me. I created a new 1GB ram cache as unformatted, rebooted and formatted the new ram cache as NTFS in the windows 7 disk management plugin. I don't believe the cache's NTFS format would 'stick' after a reboot, so I saved an image of the new ram cache (with the symlink I talk about below) and used the Dataram option option to reload the image on startup. The NTFS format now 'sticks' after a reboot.
After the NTFS cache disk was in place I used mklink (built in windows 7/vista command) to create a symlink to the ram cache. My temp folder had been f:\temp\splogs and I wanted it to be h:\temp\splogs, which is the ram cache.
The command for me was, after changing the directory to C: at a command prompt .... mklink /D h:/temp/splogs f:/temp/splogs.
That symlink also survived a reboot, but in any case I wrote a small bat file to invoke it just in cache.
As for file size, it's too early for me to say, but I did notice that after unlocking an existing splog.log with unlocker and deleting it, the new splog.log file that was created has not been written to. That's probably not a good thing, however password manger seems to be working.
It's definitely not elegant. as mandrews seems to allude to. I run password manager manually so I'd say this tweak works well, but is only manageable on a machine with a user comfortable with such procedures. I wouldn't say it's a set it and forget it fix, because of the file splog.log file size increase before I unlocked it, but it is better than what I had before.