Has anyone had any difficulty upgrading from Entity Framework 1 to Entity framework 4?

I'm looking at a project that has been developed and maintained with Entity 开发者_开发知识库Framework 1 that is relatively stable at this point. I'm wondering if people have ever migrated a project like that to EF 4 and if anyone can share any particular difficulties they may have had. I know there are a lot of benefits to look forward to but I'm trying to assess the risk involved if I upgrade. Will it create a lot of unexpected behavior for someone who is accustomed to EF 1? Any input would be appreciated.

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This is the only significant problem I've had. It may or may not affect you. There's a workaround, but it's annoying.

If you're using pregenerated views you'll need to manually change your build events to use the .NET 4.0 EdmGen.