Preferences Keep being forgotten - Corrupted?

Question

So every now and then the Finder will lose my View preferences and things will pop up in icon mode instead of list mode(this has happened on a folder that I use regularly and never change the view mode on - so no, it isn't that I opened a new window I never changed to 'list', or changed to 'icon' and forgot I did it).
I used to ignore the View issue as it was rare, but now Mail is having issues remembering it's preferences. A couple of times it's reverted my Toolbar settings to the default when I open a new message window or make a reply.
I'm going to delete my prefs for the Finder and Mail and see what happens, but the frequency of these issues is so low(about once every few weeks), that I won't trust it's resolved until I've had no issues for a couple months.
Are my preferences corrupted, or is something else going on?
On a potentially unrelated note, a number of times my system has forgotten I've left a window open on shutdown and it's not open anymore when I next startup. It sounds like it could be a PRAM issue, but my clock never resets when that happens, so I wonder if it might be related to the preference problem.

Answer 1

Well, it's now forgotten that I had set the desktop arrangement as 'snap to grid'(after having deleted my preference files and reapplying my settings).
This is getting annoying.