Hmmmmm. Doesn't look too bad but it might be worth replacing anyway just to see what happens.

There's heaps of capacitors on ebay, but just had a quick look and this will do http://www.ebay.co.uk/itm/10-x-22uF-...item4604b0e1af

They are not surface mount like the original but should be easy enough to solder in place. It'll do just to see if it makes any difference.