As much as we all love the level of accessibility that is available 'out of the box' with an iDevice, we probably all feel a sense of apprehension when a new update to iOS is released. We click the 'Update' button, silently hoping that accessibility problems from the previous version will have been fixed and that no major new problems will be introduced.
It's certainly difficult to imagine how it could be any other way. Apple undertakes extensive beta testing of every iOS version, but it simply cannot replicate and test every possible user scenario. This is why each and every previous version of iOS has included some issues for VoiceOver users, and why the sheer size and scope of changes in iOS 5 suggests that it will be no exception.
So, what should you do when you encounter an accessibility issue? Well, the first (and probably second and third) thing to do is to check that it's not a case of user error: are you doing what you should be doing? If the answer is 'yes' and the problem persists, check online to see if others are experiencing the same problem (check here and on the various mailing lists that are available).
Once you are sure that there is a problem with accessibility in iOS, you need to let the Accessibility Team at Apple know. Don't assume that they will simply 'know' about this problem, or that somebody else will tell them. It's far better that 20 people report a problem than nobody. Also, don't think the problem is too trivial to bother them with. It's why they exist, and we all know that it's quite often the trivial and minor problems that we find the most irritating.
You can contact the Apple Accessibility Team via email at firstname.lastname@example.org. When you do this, be sure to provide a clear and concise description of the problem. Tell then what iDevice you are using, what you do, what happens when you do it, and what you expect to happen. With this information they should be able to replicate the problem that you are reporting. For a software developer, being able to replicate a problem goes a long way towards being able to fix it.
If enough people take the time to report accessibility issues to Apple, then perhaps the next iOS update will have less cause for apprehension.