I just bought an '07 Adventurer 10T. It is a fairly heavy fully kitted out 10' rig. While I was measuring for tie downs etc the other day, (it is still at service dept getting an awning etc), the main service guy was confirming what we have been saying. NEVER leave your camper just on the jacks when it is off the truck. At minimum, a couple of saw horses with 2x6s on top running the length of the floor are recommended. The jacks are only to loft it for installation and removal from the truck.
I know some people do leave them on the jacks fulltime, and it is your camper, do as you like. However it is apparently not a good idea.
'98 Dodge 3500 CTD NV4500 complete with a crap load of goodies.
'11 Rubicon Unlimited OME heavies
'07 Adventurer 10T
Sin niņo, tres perros y mucha tabletas de surf!