Yamaha DTXpress/DTXplorer/DTXtreme

I had the same problem with one pad clamp after 4 months of use.  I 
was tearing kit down 4 times a week for church play and re-assembly 
at home.  Went to Mars Music where I purchased the kit and they 
ordered a new clamp for me.  However, they gave me great advice.  
When removing pads, just undo clamp under pad, not the clamp that 
holds the pad arm.  I should have known that.  Since then, no 
problems since I pad angles and placements don't change for me.
Hope this helps someone.