A user forgot his password. Then he will use the "i forgot my password"-function.
The board will send a e-mail. In this mail is a link and a new password. The given password does not have the complexity which are demanded by the settings in the acp.
On my board you need to use small and capital letters. But the password which is send to the user only contains numbers and capital letters.
I think this is a bug, which should be fixed. I would just suggested that the password always uses numbers, capital and normal letters and special characters.