[ruuk]

when in subscriptions, viewing a subscribed thread, then clicking back, it takes you back to the subscription index page, this is good. But when viewing a subscribed forum, and clicking back, it takes you back to the active forum main index, not the subscription index page.

This is because when when you view a subscribed thread, the subscriptions window doesn't close, so when you close the posts window the window is still there. When you view a subscribed forum, it changes the contents of the subscriptions window to the threads of that forum (the subscriptions window is just a threads window with different content).
FB used to only handle thread subscriptions, so when I added forum subscriptions, this was the easiest way. Also I was trying to avoid stacking another layer of windows on top of the subscriptions view (ie Forums::Subscriptions::Threads:osts when currently it is always Forums::Threads:osts if you consider the Subscriptions view is probably mostly or all threads anyway for most users). I'll probably change it to layer on top of the subscriptions view as you are expecting, maybe with an option in settings for the old way if I still think that makes sense.

If you want to quit FB and you by accident hit the back button for a few seconds to long you get the "Do you really want to quit Forum Browser" message many times, which you have to answer.

Well, this is because holding down the back button for a few seconds actually sends many button presses in a row which apparently get queued up and then sent to FB. I'll see what I can do about it.

Is there any chance that you can add the "OK" button to the message windows for "User extra info" & "View forum info", because these two windows leave screen debris behind in Transparency skin, when you hit the back/escape button to get rid of them, where the other various info windows with the "OK" buttons doesn't leave screen debris. Is this possible for future info windows as well ?.

The reason the info windows don't have an OK button is because they are meant to be scrollable and start with focus on the scroll bar. Putting an OK button on this sort of dialog would make the user expect they could press the select button to close the window. If the OK was there and I put focus on the OK button, users might not realize they could focus on the scrollbar. I don't want to change this because of a glitch with Transparency/XBMC (this is and previous artifact issues you've mentioned sound like a bug that needs reporting) but I think I could make the button optional from settings.

I miss the blue skin of the old xbmc.org forum(IE "Use forum colours" option of old), what files do I have to mod to do this , or is this a nightmare?.

When FB started, all forums were handled individually with a bunch of url, scraping and formatting definitions in a file for each forum. The colors were manually defined in this file like everything else. I basically had to look at the forum and see what it's color scheme was and put some color definitions in based on that. This was fine because I was setting all the other stuff for the forum anyway and there were only about 5 forums .
Now all of that is gone. or Forumrunner doesn't interface with the forum pages at all, and even with the Parser browser it would be basically impossible to determine the forum colors automatically.
Also, at this point, all the code for handling the color definitions is gone. It was kind of messy anyway, and the way it was done made it hard to make alternate skins for FB.
I have thought about making it possible for the user to define colors for each forum. I definitely need to make it possible to set the color under the logo because some logo's don't work on the color set in the skin.
So maybe something someday. I liked the forum colors as well (which is why I put them there)