Releasing connections to server

There's an open ticket on this, and correspondence to which IMH has not replied. My customer's IP is frequently being blocked from accessing a web page I prepare for him. A dozen users max are showing up as 50 simultaneous sessions, causing IMH to block the IP. It's no help that sometimes IMH says it's 50 that blew the fuse, at other times 200. How do we work within your thresholds if they're moving targets?

TechSupport says it's probably my coding that's responsible, that connections are not being released. As I see it, it's not up to my HTML code to secure or release a connection, that's a lower-level handshake between the browser and server. There's some PHP that parses a file and sticks it in an HTML wrapper, and the HTML self-refreshes with JS setTimeout("location.reload(true);",mS) so it's the client doing the counting down, not the server. We're trying to work with you, IMH, but not getting any useful advice other than "upgrade to VPS" (of course!) So what do we look for: (a) Apache settings? (b) PHP opening and not closing a file (checked that)? (c) There's something wrong with self-refreshing in JS?