Sorry, Norah, I've never heard of this before. But it's certainly possible you've found a bug.
Have you contacted Adobe or filed a bug report?
Those disk sizes are small for PRE. If it is writing temporary files to the C: then 32GB can fill very easily. I once had an out of disk space problem with 85GB free. I freed up another 100GB and all was well.
As your disk sizes are small at 160G total you may need to rethink about your partitioning to maximise your free space (that should also be defragmented) by recombining. Others will suggest that you should not use partitioning at all - but my system works fine with my primary drive split into three partitions (C: 100GB, D: 100GB, E: 264GB).
So free up as much extra space as you can, run Disk Cleanup (and if your system works fine remove all but the last System Restore point) and then Degfragment.
Insanity is hereditary, you get it from your children
With this partitioning scheme, if I understood, the D:\ partition is only for the system backup (a common practice with some companines, like Dell, etc.), and should not come into play with normal computing. It is not my first preference, as I like having removable media with the bull backup, but some companines like this method.
However, that does not address the tiny HDD space. If one is on a desktop, adding additional physical HDD's is the answer. If on a laptop, then externals are the only way to go. This ARTICLE will give some tips on how to use external HDD's for editing.
An update, finally. I have totally revamped the disk partitioning and storage. I now have C: 160GB PATA (System, 110GB spare), F: 500GB SATA (Data) This leaves me with about 350GB on F: for temp files. All data storage now on a Linux server with 1TB SATA*2. No further issues have been found. Thanks to all for your suggestions and support.
For Assets on the server, I would Copy those over to the Project HDD, for editing.
I normally structure my Projects, where the [Project Name] folder is the root, though it might appear below a Client's root folder.
I then add sub-folders, such as Videos, Audio, SFX, Music, etc. below, and will Copy my Assets into the appropriate sub-folder. The originals are all safe on my NAS. As I also locate my Scratch Disks below my [Project name] folder, when I am done, I can quickly Delete the root folder, and eliminate everything with it. As I am only working from Copies, I never touch my originals.
Good luck, and happy editing,