Picking up ATC from 300 NM away? Frequency bleed?

Last night while flying from Teterboro, New Jersey up to Ithaca, NY, I was
talking to Bingamton approach (located in south central NY state) and
cruising at 8,000 ft.

On the frequency there were several calls from aircraft but not one was
answered by ATC. At first I thought the controller was missing the calls,
but then I heard one of the calls quite clearly: "Akron-Canton Approach,
this is ..." Akron-Canton is located in Ohio, about 300 NM away from my
position and sure enough, they share the same frequency as Binghamton
approach.

After mentioning the call to the controller, he responded that there had
been some complaints of what he called "frequency bleed" the last few days.

Is this pretty common? What causes it?

--
Peter