Bane of my current job: not only are dev, test\QA and production database names different, the schemas within each are different as well. So inside the dev database I have devschema.table, inside QA it is qaschema.table, and in production it is prodschema.table. I have yet to find a code compare tool that can handle this issue. Sure, I can ignore schema on object existence, but the code within the stored procedures? If you know of one, please do share. We do not have any sort of source control in our shop, I worked with a TFS expert at Microsoft, and he pretty much threw in the towel after a few hours. It's on my to-do list for the next year, to implement some sort of source control on database objects. I'm afraid I'm going to have to invent my own at this point. No one to blame for this head-shaker except the vendor who designed the application this way.
This is just an idea, so I am not totally sure it will work since I haven't experienced your situation. Still, what if you use synonyms? This way you could obscure the underlying dev/qa/prod schema issues. Then at least your stored procs could be the same on all of the databases. I am not sure if redgate sql data compare works on synonyms or not. Anyway, it is an idea, perhaps it will work for you.
Ben