Well... I don't think all stands are made cheaply... so there's no real "OH MY GOD!!!" reaction needed to go run for the hills and inspect everyone's stand. Would be a good idea, but I wouldn't panic
Wood, just like humans and the pretty fish we love so much, is alive... even if it is long "dead" and in cabinet form. It will still swell, shrink, and change with time. No two pieces of wood are the same, so, likewise, the constuction from stand to stand will differ. There's always the chance that a nail gets driven into a knot or a vital part of the grain that causes the wood to split or weaken... even the way it is cut. This is a possible cause to this particular problem, or other 1094238 reasons (too much weight being one of those). BUT, after having looked at some units from a certain unamed LFS
... *coughpetcocough* I wouldn't waste the $169.99 that it's going for, since it would have to be braced anyways.
Just be careful if you choose to reinforce your stand... if you're not and you have no idea what you're doing, the modifications you do might end up making the stand weaker. 8O Many bases out there are made of particle board, and will not take screws and nails well over time. So, in effect, you can make an expensive block of swiss cheese if you drill the heck out of it.