I just filed a bug over on Microsoft Connect about a problem in Expression Interactive Designer with the design time support for an ObjectDataProvider where ConstructorParameters are used. I noticed it a couple weeks ago and never got around to filing, but I just got back into working on the project where I was having the problem and noticed it’s still broken even in the latest build (currently Sept. CTP). There’s is a workaround that I included with the bug, but it’s super annoying and the target audience of EID definitely wouldn’t want to have to be doing it every time they went to build their apps.

Anyway, if you check out the bug make sure to express your concerns for it being fixed by voting.