Save Window Positions?

Greetings, all. I have Gimp Portable 2.4.5 running on a Thinkpad T61 running WinXP. I'm having an issue where it will not save my main window position (the one with the tools on it). I usually have that window on the far left, sized the same height as my screen, and the Navigation/Histogram/etc. window on the far right, same height. I go to preferences and save window positions, but it doesn't seem to "stick". I'm not using the background window plugin. The only thing that *may* be odd is that I use two screens. But I always keep the GIMP windows on the laptop screen. Any ideas? Thanks in advance.