WP7 - January tools update explodes my application. What'd I do?

I've Googled around a bit on this issue and haven't been able to come up with anyone else having an issue to this one, so a) I apologize if this is a known issue; and b) I'm thinking this proves that I must be doing something horrifically wrong, yeah? :-)

My application has a very rich landing page which is the first page that is shown after a new launch. It has a panorama control, a large background image (but much smaller than the 2000x2000 limit) and recurring and ongoing animations. Prior to updating my tools to the January refresh, this page ran relatively smoothly. After updating and running the app in the emulator, the background of this page is white (despite the fact that the emulator is on the "dark" theme), performance is quite poor (both in terms of swiping through the panorama and in terms of my recurring animations). When I run the same project on my device, all is well (since, quite obviously, my device's OS is not on the updated image).

Clearly I must be doing something grievously wrong to merit such a cataclysm, but I'm not sure what it might be. I've tried disabling bitmap caching in the places where I'm using it, removing third party tools I'm using such as Peter Torr's awesome tilt effect and his memory usage counter, and several other hail-Mary-style moves, and the problem remains. I also looked through the provided resources and change log to see if perhaps something related has changed, but I didn't see anything.

I'll try to provide example code later if it would be of any use to any would-be saviors out there, but the app is pretty complex and large in terms of lines of code and file size, 开发者_开发知识库so it might be a bit tricky. i just thought I'd toss this out there and see if anyone might happen to see it and think of an obvious solution.

Thanks so much in advance for your time and help.

P.S.: I cross-posted this question on the official WP7 dev forums. Sorry if that's against the rules - I'm not a regular SP-poster, as you can tell. If it's a problem, let me know and I can delete the other post.

I was ultimately able to resolve this by creating a brand new project using the updated tools and copying my code, assets, and relevant project settings into it. The app now runs flawlessly on the emulator (or, at least, the flaws in it are my flaws and not the emulator's :-)).

I believe I originally created the project on an earlier version of the SDK, so maybe I had some kind of invalid or incorrect project settings. If I get a moment later, I'll compare the project files to see if I can identify a setting or difference that explains the disparity.

Thanks to all who looked (and to Matt, who even responded :-)). I'll report back if I have any more information that might be of help.

UPDATE: Updating for anyone who might be having this issue as well - my resolution above was a false positive. Creating a new solution and copying stuff in does indeed work, but only until you save and close the new solution. Upon reopening, the problem recurs. Grrrr. I'll post back if I come up with anything else.