[Xastir] Memory question

[Tom Robson, ve7did]

I am running Slackware 9.1 with 2.4.24 kernel with 262M physical memory with 
100M swap on a 50 gig partion.  Using KDE.  Hadn't rebooted the box for 2 
months.

Noticed the machine was a little sluggish recently so had a look at TOP and 
noticed that all the memory was used up as well as the swap.  l also looked 
at the System load graphical interface and it agreed with TOP.

I killed all of the running apps including xastir and memory 'used' and swap 
did not change.

What's left?  so rebooted... and memory useage went down to about 140M and no 
swap usage.  I image that is about normal for KDE.

Started up xastir with no maps and consumed a bit more memory. Killed it and 
memory went back where it started. Started xastir again and started loading 
shapefile maps and now memory usage started to escalate very quickly.  Got it 
up to the 262M quite easily.

Now, I deselected the maps and memory useage did NOT drop.  I killed xastir 
and memory useage still stayed up.  It appears as though the shapefile maps 
are keeping the memory useage up, even if you have deselected all the maps.

I'm not sure how all the swap got used, but I expect I was messing around 
loading a bunch of more maps or something.

I tried this same scenario twice and it is duplicatable.

Any thoughts or am I missing something or don't understand memory useage?

...73 Tom