In a winforms project with a reference to a WCF service R# doesn't detect changes made when the service is updated.
For instance, say we have a function that takes no parameters in the WCF service and we later decide to add a prameter to that function. So we make the changes in the service and then in Visual Studio we do the Service Update. Visual Studio without R# recognizes the changes and it shows up in the intellisense. But with R# the intellisense does not know about the change. Thus the RED indicaticator show errors even though it compiles fine.
The only way to correct the problem is to close the project and reload so that R# will parse the files.
This is not a show stopper since it does compile and run but it does confuse the programmer and everyone knows we are confused enough now.