To blame the "hosts" isn't a fair bag. This problem has existed continually on one platform for quite some time. Get it fixed, then move forward. I'm sure Avid's 3rd Party developer team wouldn't look too kindly on you placing the blame at their feet. No, the ball has been in your court to get things up and running under PT 8 - and that is a separate issue from Snow Leopard compatibility or any other hot fires you might have on the kettle.
Regardless the size of your team or the incredibly large workload you may have in front of you for various issues, I take issue with the fact that you have not provided simple *voluntary* updates to your user-base. It takes all of five minutes to type "we've made some progress on the bug today, but uncovered a new issue - expect a new version or beta to be released within the next [few days, week, month, etc]." Your lack of doing so suggests that either you are not working at all on the fixes, or that you simply can't be bothered to tell your users if you are, which makes you seem like you are not interested in supporting your product. Both things have to be in place to be considered a successful software development team - and I would urge you to consider this as you move forward. So far, you have posted reactively, and not proactively.
Rely on your user-base to help you test by offering beta versions intermittently. This makes your work evident and showcases your level of support, while at the same time letting you off the hook for instability during the beta test cycle. If you don't have the tools to do that, then simply update us on your progress every week or two. Then we don't have to keep coming back angrier and angrier that nothing new has been posted, even though you have made promises to the contrary. Set expectations properly - don't tell us you "plan to have a beta ready in the coming days" and not have anything ready a month later.
Lastly, offer a level of support that suppresses posts like these. It does nothing for me and only makes all involved look bad.