Repainting screen drag

[andy]

Hi

Using Xfce 4 on a Slack 10 machine, single user, no network, no high 
powered toys or peripherals. CPU is an AMD XP2400, with an ASRock K7VT2 
mobo, a RiVA TNT2 graphics (+ 32 MB DRAM), two mem chips PC100 @ 262MB 
RAM each, std 17" Packard Bell monitor.

Over the last few days I have found that whenever I open a new window 
(via an app, or a pop-up menu) or unshade/unminimise one, there is a 
noticeable delay from clicking to the screen being repainted to show the 
new window/menu.
I was using PLT's DrScheme IDE last week and over the weekend, had one 
Firefox browser, two email clients (KMail & Thunderbird), a shell 
window, an OO.o document, and a small window for my CD player. I may (or 
may not) have been on-line. I always leave my machine on.
I examined top and could find nothing out of the ordinary. After a 
couple of days, when executing a program through DrScheme it began to 
really take a long time and mred (the app's name) was chewing up resources.
Today, without rebooting or logging out and then back in, but with 
DrScheme, the browser, the CD player all _closed_ I am noticing that 
there is still a delay in the screen repaint.
I would have thought that the memory would have been released once the 
apps were closed (or, even when minimised I think as per the kernel 
architecture, I think??), and DrScheme (written in Scheme) has a good 
rep for efficient garbage collection and memory release.

I am tempted to logout and login again, but before I do do that ...

My questions are:

1. Has anyone else encountered this? A Google search didn't show up 
anything that seemed connected, but there again there are hits to 
several orders of magnitude for the terms Xfce, screen repaint/ing, etc. 
in different combos, so I admit I didn't exhaust that resource.

2. I am wanting to trace the cause down and sort it out if I can, but 
beyond invoking top, I am really not sure how to proceed. This may not 
even be an Xfce question, but thought that it would be a good place to 
start.

If it would be of use in drawing an opinion on this, I am happy to 
fire-up DrScheme and the other items mentioned previously and read off 
top again. I would have thought though that the memory used would be 
released again, so I am not too sure if this is memory or an indicator 
that my monitor should be read it's last rites.

Anyone got any thoughts on this?

Cheers

Andy