I have to revoke my posting from yesterday.
As I see, aMule crashed just 30 Minutes after my posting yesterday, at 23:03.
There is just one error line in /var/log/messages:
Sep 18 23:03:20 localhost kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d2/0)
After automatic restart at 23:04 (script), aMule is running faster again.
Memory usage is now (09;15) 63 MB RAM (of 92 MB) and 45 MB swap (of 94 MB).