I have just had the same problem but on closer inspection I found the water was coming from a loose bleed valve cover on the back of the pump,the way the water trickles down made it look like it was the pipes when in fact it wasn't.
I removed the large metal cover and just tightened the bleed cap (on the back of the pump) then pressurised the system and bled all the rads.....everything is fine now.
Paul, March 2010
I had similar problem on vokera mynute 16e, turned out to be the expansion vessel leaking.
