If the response is "I had this problem, tried this, etc etc etc, and ended up at the Apple Store", then that's a different scenario. Yes, it may be a hardware issue, but if the machine is out of warranty, it's going to cost you money to have them fix it there. However, if we give out some useful information (such as the fact that the bezel is the culprit), then it gives them the ability to determine whether it would be worth spending the money to fix it. In short, let's diagnose the problem as best we can as a community before sending someone to the Apple Store. Saying "Go to the Apple Store" as a first response is akin to saying "Get off the forum, I don't feel like helping".
I personally hate the Apple Store and the dependence upon it. There's no reason why one can't crack open one's Mac and replace the necessary parts as one often does with a PC. I do it myself, and it saves me a pile in labour and parts. Yes, in this case, the parts pretty much have to come from Apple, but the labour doesn't. Apple used to consider the midplane to be user installable on G5 iMacs, so it's not much further to swap the front bezel. Considering that it's 1.5-2 hours to do the job, it's a fair amount of money to be spent on raw labour, when the part is quite cheap by comparison. With the advice I've given here, jenrafi can determine whether to obtain the part, where to obtain it (I'm sure eBay has some), and how to install it. I didn't just pat her on the head and send her to the Apple Store, when they're going to know the same amount (if not less) about the problem as I do.
In short, we all know the problem can be fixed by going to the Apple Store. However, when people choose to ask a question here, it's a fair presumption that they want the advice of third parties, and not just Apple's service manual. Let's give the advice, and not just fob them off on the people that they explicitly chose not to consult in the first place.
As a final test for the actual bezel, insert a disc upside down (label facing the rear of the machine), and see if it lets it fly. The one I worked on would hold on to a reversed disc, but not a properly inserted one.
The official course is to replace the optical drive. However, I've found that the issue is more often the front bezel, and it's failure to line up perfectly so as to catch the disc. 
