Wow - that is a lot of inquiries. Have you checked your spam filter on your email? I have also heard from someone else on another forum, that she was blocked by VRBO/Homeaway as she had sent out too many inquiries. VRBO/Homeaway is trying to cut back on spam emails that we owners receive - maybe you were flagged because of the number of inquiries.
Check your spam filter first, then give Homeaway or VRBO (whoever you had inquired through) a call. Or you could try sending out a few inquiries from another email address (don't send 75 again, maybe just 10 to see if it works).
As an owner, I certainly hope the inquiry feature is working correctly.
Actually, I am starting to wonder if I am having the same problem as you. Last Friday I sent out maybe a dozen or so inquiries, also regarding homes in Florida, and received only 3 responses over the Memorial Day weekend. Maybe owners weren't checking their e-mail regularly last week because of the holiday? I don't know but it is very frustrating.