Sometimes when you have more air coming in than out , it could create hot air pockets in the case. In your case, you have 2 intake fans and 1 exhaust fan. That air coming in has no where to go, so it just heats up in your case.
Anyway, Your computer is running much cooler than before you had added those fans in. Good improvement. I know Athlon xp 's use to run hot partly because they didn't use heatspreaders like the cpus of today. They were just exposed tiny cores.
If you don't mind cutting into your case you could add some more fans or even enlarge the current holes for a bigger quieter fan. If you own a rotary tool, it's fairly easy to do. It's a great way to spruce up an old case.
OK thanks for the information.
Maybe I should add 1 more exhust fan or take away 1 intake fan.
Either of these options will even them out.