Yes, it is known error, but not in Bombono, it is in GTK2 that Bombono uses.
My quotation from http://sourceforge.net/apps/trac/bombono/ticket/86
Well, it is the bug, introduced in GTK+ library, 2.24.11, and fixed in 2.24.15; it hurts all GTK programs in Ubuntu 12.10, i.e.:http://ubuntuforums.org/showthread.php?t=2101074https://bugs.launchpad.net/soundconverter/+bug/1063724
The workaround: you have to select the folder but don't enter into it, and then finish the File Chooser dialog with pressing the button "Open".
Users are encouraged to update to GTK >= 2.24.15.
The nasty bug, yes.
Because of this I explicitely prohibited to choose the home directory in 1.2.2 .
P.S. I am sorry about your data loss.