Don't put Notes Data on a mounted local drive

I added a new harddisk to my PC recently. Since all my data lived in c:\data I moved that to the new drive and used XP mounting capabilities (do I hear: they borrowed that from Unix?) to mount that drive back to c:\data.
It took me a while to assess the impact. Notes became partly unstable especially when opening mime email while replicating. I first blamed it to the fact, that I have more than one client and beta ones too. Then I realized, that in the mounted directory explorer sometimes behaved irratic, not letting me move, rename or delete files.
So I switched from mounting the drive to the 'normal' way (for Windows) and assigned a drive letter. Luckily it is just one entry in notes.ini to teach Notes its data location. Since then I had no more crashes so far.