Chat Issues - Deny request still allows messaging from sender, and request button fails on profile


Two issues with chat, and one general question.

1. Issue: If User-A requests a private chat with User-B and User-B hits the "Decline" button, User-B's private chat window *does* close. BUT, if User-A continues to type and send a message, the chat window will immediately open on User-B's browser. User-B's choice to "decline" was futile. User-B can then "leave chat" as often as he wants, but each time User-A continues to send messages, the chat window will keep popping up on User-B's page.

2. Issue: If User-A goes to User-B's profile page and clicks the "Available" button across the top of the profile, it does not invoke a chat session.

3. General Question: We're still preparing and testing our site, and Chat performs very well. Realizing that of course server load impacts such things, we're on a dedicated server configured as shown below. Can we expect chat to perform well with, say, 500 users, 1000 users?

Intel Core i3-3220 @ 3.30ghz
4gb RAM
500GB DISK / 7.2K SATA

Thanks for your help and insight!