Folders and program window settings are not retained between sessions

I've Googled this and searched through the various Windows groups, but haven't seen a topic like this posted. To be brief, my windows will not return to their pre-set sizes or positions from session to session. They used to, but no more.

Up to about a month or two ago everything was working fine (using Windows XP Pro, SP2), but lately it seems that many of the programs I use forget their basic settings -- like window size and position, and options and preferences -- from session to session. I turn my PC on in the morning and off at night, but during the day I might reboot once or twice.

As one example, sizes and positions of the My Computer window and all folder windows, as well as settings of programs like WinSize: http://www.freedownloadscenter.com/Shell_and_Desktop/Desktop_Window_Managers/WinSize.html are no longer retained from session to session.

Here is a description of the WinSize program: "A taskbar tray application for maintaining window positions and for helping forgetful windows remember their proper positions and sizes. Simply run it and start storing those window positions. It will automatically apply these positions whenever the windows you have selected are moved or resized from their original place - It will even remember the View settings you have chosen (Large icons, small icons, details, list) and it will also remember whether you had the toolbar and/or statusbar on in a given window."

Well, no more! It worked fine up to about a month ago, and in the last few days won't even work from one session to the next. Even this program, which is designed to prevent windows from forgetting their settings, won't work!

An additional, similar problem I'm having with PopTray (http://www.poptray.org/downloads.php) is that it loses my entire e-mail accounts information and preferences on average once a week.

I'm not doing anything unusual with Windows, and I have already followed all the tried-and-true suggestions posted in the various Microsoft WinXP newsgroups, but none does the job.

Any clues or suggestions? Thanks in advance.

Frank D