Your issue could be under-inflation causing the bead of the tire to roll in on the tube. At any rate, trailers can sometimes sit for a while between uses. Tire pressure needs to be checked before every haul.
I run Maxxis Hookworm tires on my trailer. Just noting that in case you need new tires. They are much beefier than stock tires. They also take eons to break down from lack of use. They still need proper pressure though.
Last edited by JoeyBike; 06-22-14 at 01:31 PM.