I've been trying to diagnose a similar (but different) performance problem lately on my machine. In my case the system (particularly GTK apps) are agonizingly slow every 3rd or 4th time I boot up.
Well, as much as I hate to hear anyone suffering, I am glad that *someone* has experienced something of the GTK slowdown I have! Mine is all the time though.
One thing that was mentioned to me in the many threads I've started on ubuntuforums.org to try and solve the problem is that performance degradation over time (during the same session) can sometimes be attributed to a memory leak.
How would I trap a memory leak? Is there some kind of logging software I can run that will decide this issue? Bryce has given me a list of things to try, but perhaps there's something more specific to memory leaks.
This is likely not attributable to Inkscape but possibly to some other application or driver. Have you changed/installed anything that made the problem start happening?
No. Really. I have had this same machine for about +-8 years. The m/b is about 3 now cos lightning had a talk to the last one. It's the same CPU. 512K of my RAM is about the same age, the rest is about 1 or 2 years old. This same machine with the same IDE cables has run everything from Win 2000 and XP to Fedora 1, Fedora 3 and Ubuntu Hoary and now Kubuntu Dapper.
Every time I ran anything to do with GTK it was slow. Always, without exception. KDE quickly became my favourite because, frankly, I had no real alternative. (Ubuntu Hoary didn't last as it was Gnome.)
I have asked about this over the years and I mostly get "shutup you are tripping" kinda responses. *shrug* I pretty much put it down to my AMD chip and the binaries out there being i386.
The many versions of Linux over the last few years is chiefly what makes me think it's not a certain driver or version of anything, but I'm really no expert.
The next thing I want to try, but time (and nerve) has delayed me, is to compile Ink 0.45 on my machine and see what I experience. I suppose if it's a GTK problem then I should compile that too! Argh.
/d