Problem with bloom filter on one specific machine


I’m following the tutorial : How to make a neon vector shooter

The bloom filter work great on my old macbook pro, but it is completely broken on my newer one. (late 2011, 2.2ghz i7 + AMD Radeon HD 6750M 512 MB) The old one is a late 2008 with a GeForce 8600M GT with 256MB.

How can I debug shader/filer? or does someone knows what could be wrong?

I used the same code as the tutorial.

thank you