Fingers catching unplaying string

[norvegicusbass]

Currently I am teaching myself I Feel Love by Donna Summer ( I understand this was a synth bass track on the record but hey... ) trouble is when I try to bring it up to speed I am kind of playing it harder and my plucking fingers are impacting on the string above ( A string impacted while playing D string ) giving loads of extraneous sound. I am still playing a Lindo acoustic without amp and without the ability to adjust the sound quality but I still want to nail this and play it at the speed on the record without all these extra noises. Any thoughts how to mute these strings or an effective way to mute when playing over three strings at speed?

Edited February 24, 2011 by norvegicusbass