Apparently its the ethanol in the fuel leeching through the plastic tank that causes the bubbling. Unless you get the inside of the tank sealed respraying is a waste of money as it will just happen again?
I'll have to look into it , I have had 2 bikes resprayed in the past by the same sprayshop so I might pop in and have a word with them ... They might be able to do it for me or suggest someone local who can .