Crispy, I guess you already know about this (then you can ignore it) but I'll post it anyway (just to be sure)
Say I have my personal number of posts per page set to 20 and the forum uses default 10.
If I found a forum page through google or a post notification.
I visit the page, want to reply and open a new window to login.
Then refresh the page the post was on to reply. (still clear...?)
The problem is that if the inital page was on the page 2 it now could be on page 1 because te maximum number of posts per page changed, since I'm logged in now.
But the forum displays an empty page 2 with no links to go back to page 1, and the link on top of the forum also keeps sending me back to the same empty page 2.
The only way to see the thread is to reopen the original link I found.
Hope it's clear and I'm not the 32nd person to post about this...

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I found a workaroud....
Remove the "threadpage/x/" part of the url and you will be taken ot the first page...
Quite simple in a way....

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