You're misunderstanding sampling. A couple of things:
1) Your signal source has a "sampling frequency" of 5MHz and you are asking it to generate a cosine with frequency 96.5 MHz. If you've had a DSP or linear systems class thing back to nyquist (damn kentucky derby means googling for nyquist is now full of horses)
2) Let's say you tune the USRP to 96.5MHz and there's a station there. What do you expect the received spectrum to look like? For a hint look up complex baseband.
Also, it helps people help you if you explain what you expected and what actually happened.