Everyone needs to be sure they have load range "C" or "D" tires.  My 3124 was upgraded from a "C" to a "D".
The D's carry 65 pounds.  We have been through the blowouts on two C's and now with the D's we only had one Carlisle blister.  Have had a Goodyear on one side and a Carlisle on the other and towed over 8,ooo miles since July of 2001 and had no more tire trouble.  Did read that with a car tire, an extra 2 pounds of air would increase the speed rating by 10%; so to make up for potential problems with tire gauges, I now keep the tires at 67.5 pounds cold. What I have not done is change the label on the trailer to indicate that the tires are now D's and need 65 pounds of air pressure.. Remember a trailer tire is only speed rated at 65 MPH.  (I tow at whatever the legal limit is and am towing some at 75mph.)