Having the same problem here, but with movies, it found 69 out of my 156 movies (local disc), after that it just stopped recognizing through imdb for some reason. Manually added the rest.
All my files are named title(year).extension, and even though there will be some movies there are hard to find, it even leaves out movies where a manual search only reveals one hit.
I know we're just in alpha, but hey, nitpicking is a part of it, no? ^^
Running Boxee on a dedicated HTPC:
Windows 7 64-bit.
Intel® Dual Core Atom™ 330 @ 2ghz.
4gig Mushkin RAM.
NVIDIA® ION™ GPU.