D25 is a 1N4148 (Jaycar have them so they are easy to get)
D23 is a 1N5817 Schottky rectifier diode, and the most likely culprit to cause your batteries to be drained quickly, as they would be trying to power everything on the +5 volt line.

Jaycar don't have the 1N5817 (not sure if they have an equivalent though)   but RS components do;

http://au.rs-online.com/web/p/rectifier-schottky-diodes/8051012/