My bad for the necro, but you could try disabling the navigational warnings (that shouldn't be too hard...?) - it comes down to whether you'd prefer the double post bug or a lack of warning about losing your post content.
Good thought. I'll see if I can comment out the bit of code that throws the message for now, see if it helps anything. If you accidentally lose your post there's still the auto-recover button so the message is not super necessary if this works around the problem. Edit: Okay, done since I've not been able to reproduce the issue myself, could you let me know after you go a few days of posting if it still happens [MENTION=7796]Xalder[/MENTION]? Thanks
[MENTION=1543]mike406[/MENTION] Well the warning definitely doesn't seem to be showing anymore, I can't make comment on whether or not its changed the double-posting though (never happened to me).