So we tend to explicitly implement most of the interfaces in our code by design. However, since upgrading from R# 6.1 on VS2010 to R# 7.1 on VS2012, I have noticed a problem relating to doing this.
When I do a Find Usages on the method declaration of an explicit interface, R# reports that there are no usages. If I do the same Find Usages, but on the method declaration in the interface itself, then I find the implementation method, but that is all. What I do not find in either case is the code that actually calls the method. However, if the cursor is on one the callers of the method, then I can Go To Declaration/Implementation without an issue.
For other interfaces that are not explicitly implemented; but instead implicitly implemented instead all functionality works as expected.
I hope that I am being clear. If not I can build up a sample solution for you.