I just came across this post so this is a little late. But could you post a link to the roller stand? They have sold a few different models over the years. I've had a couple of the single folding type of roller stands similar to this one.
http://www.harborfreight.com/cpi/cta...emnumber=95621 The difference with mine is that instead of having a lever to tighten the adjustable height it has a standard black plastic knob. I've used them both a lot over the past 4 or 5 years and they've functioned perfectly. The roller brackets have a little bit of pivot ability built into them so they sort of self-level. The knob snugs down tight. The rollers roll easily. The only downside I could come up with is that they can tip over if you push too hard in the wrong direction. But they are virtually identical to models I've seen sold by Rockler and other companies, (With respects to how and where the stand folds) so you can't just blame that only on Harbor Freight. In fact, the only stands that I've seen that are more stable don't fold up as compactly as these do.
You may well be referring to a different stand so maybe a link would be helpful. If I were to buy the new version with the lever instead of the knob and the lever broke I'd just replace the lever with a $3.00 black plastic knob. It's a bargain when compared to what the competition is selling the same stands for.
Bruce