Currently, grive RDEPENDs on boost:1.48. This isn't necessary as it works well with boost-1.49 (and supposedly higher versions as well). Attached patch updates ebuild. See Bug 407761.
Created attachment 318320 [details, diff]
Update boost dependencies to >= 1.48
Just to confirm, I am testing grive with boost version 1.49.0-r1 and it compiles and runs without problem.
I am on ~amd64.