The my templates folder should be 0755.
The template folder itself should be 0755.
The files in the template folder should be 0644.
(well, that's what they are in my installation, by default, and they work)

If those permissions are correct, then is it possible you didn't create a folder under my-templates? Should be something like:

my-templates  (directory)
	-crystal (directory)
		- all the php and css for the crystal theme here
	-superbold (directory)
		- all the php and css for the superbold theme here

The other thing is that the style.css needs to have a line in it like this:

Theme Name: Crystal

If the Theme Name is not unique, I think bad things happen. At least you see what appears to be a theme of the same name in multiple places in the admin panel. I know WordPress doesn't like themes with the same name too much, and I suspect bbPress is similarly picky.

Please post when you find the solution because I am sure it will help other people. Thanks.

//bb-templates

and

//my-templates

yet, on the admin console , i only see the default kakumei

what am i doing wrong? is there some CHMOD issue?

http://bbpress.org/forums/topic/700

Your custom templates must go into a subdirectory of
my-templates/. Like

my-templates/my-hot-theme/

This is new in bbPress 0.8.

http://bbpress.org/documentation/themes/