So I replaced my Latitude D410 with a shiny new Latitude E4300 (Intel Core 2 Duo SP9400 2.4 Ghz with 4 Gb RAM). Here are some notes about this laptop that might be interesting for others.
I first installed the system in 64 bits mode (amd64 architecture) but I had very regular freezes of the system (I couldnt finish a single kernel compilation for example). Since I switched to an i386 installation, the system is more stable but I still get an occasional freeze every other day. It might be that a more recent kernel fixes this or maybe it will be fixed with a future Dell Bios update well see, but its my biggest complaint with this laptop so far.