CPU/case temp sensors ok?

I have an Antec SLK3700BQE case which came with silent 120mm rear fan. I wanted to lower my temps and installed a 120mm/75cfm Noiseblocker fan in rear and placed the Antec fan in front. Interestingly my temps remained the same. Can this be right? I mean 75cfm is not what you'd call a silky breeze...

BTW: If someone's interested, the Antec case is great. The fan and PSU are inaudible and the HD mounting rails with rubber grommets in front of intake fan reduce both temp and noise. It also looks cool and has enough space inside.

 

Have you made sure the fans are setup to push/pull usually you want cold air drawn in from the bottom front fan then as the air heats up and rises it is draw out the rear top fans and psu,also use the most powerfull fan as the extractor to keep the pressure inside low.

 

Could it be possible that the NB fan is too efficient and draws hot air from the psu through cpu heatsink? Argh...

 

The northbridge fan is a fart in a gale it doesnt do much really have you made sure the front is sucking air in and the rear is sucking air out can I have more info on your fan configuration.