It actually fixed itself while i was away, so ill never know what happened -_-, anyway thanks for the replys everyone!
For future reference:
If you are using a pump over a ocean, you run the risk of accidentally grabbing the water source blocks as well, and due to two liquids being in the pump, the water will 'jam' the pump as it's trying to dump that item from its internal storage into a place it can't (pipes filled with Oil, in this case)...
It's a problematic issue with BC (one that Greg constantly comments about in the IC2 forums), so the best you can do is 'sealing' around the pump to lead down into the actual oil pocket. This way, the pump knows to only accept the oil down the shaft (heh heh) and to not pull the surrounding fluid into it...
(Also, a cheap underwater breathing armor would be the Hazmat helm and Compressed Air cells. So you don't have to wait for UU-Matter to fix said pumps early game in the future)...
Edit: and looking at the pic again, the pump may have though that the non source water block was the only fluid there, and refused to pick up the oil because the water 'was in the way'... I think it's an issue with the pump continually saying 'no source blocks' when it's 'locked' on a specific block.