Quote from Kurtis_
Hey, if you open up the texture pack .zip, you should see a bunch of files and folders. Go into the folder named "gui" and then you should see more files, two of which are "allitems.png" and "allitemsx.png". You may not see the .png part, but you will see those two files. Delete "allitems.png" and then rename "allitemsx.png" to "allitems.png".
I hope that's not too complicated...
The "allitemsx.png" is the old 1.2.5 GUI (that you want). I'm guessing the author is using the snapshots at the moment.
Hope this helps
Thanks man! It helped me a lot!