When choosing the wrong keymap in GUI installation mode, going back and changing it doesn't work (first selected a German keyboard, but then remembered that I had an en_US keyboard there ...). Selection stays the same (german in this case). I also noted that the keys on the NUM key block didn't work when using fdisk in "GUI" mode - don't know if this is a side affect of trying to switch the keyboard type during install. Will try this again and report it.
(found the bug entries and explainations for the NUM key part, so forget about this one ...)
This defect is considered MUST-FIX for Florence Gold release
I have tried repeatedly to reproduce this issue without success. This works for me.