Could not agree more with this statement.
As for your situation, vly- How much tension is left in the spring bar? If you're using gen 2mm springbars, those should hold fairly sprung for many, many R+I's and are what I would recommend for use. Aftermarket springbars are usually quite weak and give way after compressing 3 or 4 times in the lugs during fitting. They fail pretty easily.
If your springbars are retaining their tension after numerous fittings, then the procedure as outlined by Zigmeister is correct to ascertain the problem. Hopefully it's as easy as cleaning out the lug hole...