Latest iphone sofware update fails to synch photos in numerical order!

I've been informed that the reason why my photos on my 3g Iphone will no longer synch to it in numerical 'name' order is because the latest software update places them in 'date taken' order by default, consequently moving them out of my preferred option.

I've been told I will need to use a third party software in order to place my photos back in numerical order. Does anyone know of a way round this, and if not, can anyone recommend suitable, preferably free software to acheive this?

Many thanks.