First, you'd have to find someone who cares at D-Link. If it were my company, I would have people working overtime to issue a new firmware and fix this issue since there are a lot of DIR-655 users out there. I guess this is what they call customer service. They should send out a blanket email or post a proclamation on their website. (i.e. "We are working diligently to remedy this issue for our valued customers".) I'm ready to take my router back to the store and beg for store credit. And in these harsh times, I can't believe a company like D-Link exhibits no loyalty to their customers.
I work in software and a lot of what I do is creating patches and hotfixes for our software. However our customers are giant companies who spent millions of dollars on our software, not regular joe public.
So coming from that perspective, I would say that d-link isn't doing a very good job handling these firmware problems, however I think you are being a little harsh. They aren't communicating well, but my guess is that their development isn't in the same place as their support. I may be wrong but our support is about 4 feet from my desk, meaning when they issues they come right up to me. I am guessing that the dlink mods probably don't have that luxury, in fact they might not even be on the same continent. And if they do, then they need to tare down the barriers preventing them for getting direct access to someone.
One could argue that its impossible to figure out whats wrong since no one had repeatable steps for the freezing issue that many people have. But thats not exactly how it works. If you get a spike of people running into an issue, the first thing you look at is what has changed. So the first thing they could have done is start looking at all the changes they made from 1.21 to 1.31. Besides the SDK, it didn't look like things were that major, assuming the SDK change isn't part of the problem. So the investigation should have started there. Then dlink should have said devs are looking at the differences and they should have recommended certain areas that changes for users to test. Then we probably could have gotten it down to DNS Relay and progress from there.
So lets not say that they don't care, it may just be their environment isn't conducive to openness and getting problems fixed quickly.