Please help!

[B8YD K]

Has anyone got any idea's. My car's been chipped by Jabbasport and it would seem that under light throttle and sometimes under hard throttle my dump valve is being opened, by one of the little electronic valves that sits on the rocker cover. The valve opens the valve using the vacuum store. Does anyone know why it didn't do it when it was standard but it does it now? It's really anoying me now.

Please help

Boyd