Just a service reminder: application writers should run their applications under strace from time to time.
I just did for Gnumeric and discovered that on startup we were creating a large number of files in /tmp like this:
open("/tmp/gdkpixbuf-xpm-tmp.XAXESX", O_RDWR|O_CREAT|O_EXCL, 0600) = 9
I tracked this down to embedding icons in xpm format. The gdk-pixbuf loader for xpm is unable to load from memory so it creates a temporary file and loads from that. Ick! The solution is to fix and deploy the loader (impractical), not use xpm (possible), or to use
preprocess='to-pixdata' when embedding.