I suspect that the only way using the browsers back button causes Mudcat problems is if someone posts, hits back, sees the post they have just posted, and tries to send it again. More a case of "pilot error" than anything else. The forward button in the help forum is believed to cause problems though - from what I gather, if you post there and then go forward, the system re-posts on your behalf.

Re Nutty's problem, Max does do anything other than include the ?Messages (current count of messages count) in the URL so that each time someone posts a new page is stored in the browsers cache and the browser decides what has been visited in from the URLs - if you had a big cache, for one thread, you could have stored www.mudcat.org/threads.cfm?threadID=12345?messageID=whatever - could be 1,2,3,4,5,etc to 100+ and then there are the ragtime, etc varients and the system of course goes wrong when messages are deleted from a thread.

Other forums try to use a visited date but some (maybe all) like mine don't work that well. I've tried to think of a better system of letting a user know what they have read but can't come up with one that wouldn't involve tracking vast amounts of history for each user. The Mudcat one is probably the best.

Jon