Joanna - I'm no expert, being an unagented writer at this point, but I don't think a month or so wait is that long of a time, particularly in this case, since Book Expo America, took place in the time you're describing. Something like that would back them up for at least a week, and we have to remember, as much as we don't see it this way, that reading full requests are not their highest priority - that's their current clients.
I queried Emily van Beek on 7/2 and heard back the same day with a request for a partial (3 chapters). I was unable to honor their request for the exclusive, but that didn't seem to be a problem; she quickly wrote back to send it anyway and just keep them abreast of offers in the meantime. Generally, I think you've got to do what's in your best interest (which is to avoid exclusives like the plague). They seem like an amazing agency with quite the client roster and I'm anxious to hear back either way.
