Sigma 530 - problems?

I first bought a Sigma 530 Super (for Canon) a little over a year ago. In August it stopped working. Just wouldn't fire at all. I took it in and picked up another one to replace it will it was in for repair. That one has now started firing very sporadically.

What's more, last week they called to say they were replacing my original one, but they replaced it with a 500, so I had to send it back again, and I'm still waiting on the first one back, and now really don't have a reliable flash at all.

It seems kind of odd that I would coincidentally get two bum flashes if this wasn't a general problem. Has anybody else had issues with the Sigma 530 Super or Sigma flashes in general?

For a while I was very happy with it, but I need something reliable, and am thinking it is probably time to switch to Canon.

Sigma makes good units. They aren't great units.

My wife's 500 Super, which saw very limited use, quit working about the time the 1-yr warranty expired. My own, which was used heavily, is still going.

Sigma flashes are a lower-cost alternative to the Canon EX units, designed for the hobbyist. Pros and even hard core amateurs may want to consider something better. The Sigmas certainly aren't junk, but you get what you pay for.

I guess that makes sense. I actually thought the first one might have been my fault because I can be kind of rough on gear sometimes, but they replaced it even though the warranty had passed, so it must have been a problem with the unit. The second one, which really hasn't even been used much, is now doing pretty much the same thing so I figure it must be a common problem.

I think I'm going to switch to Canon, which sucks in terms of money, but I do prefer them for usability, so maybe this is a blessing in disguise.