You didn't tell us how you entered the password (editing wireless config manually with vi, or using the gui). Assuming you edited your wireless configuration with vi, you likely forgot to enclose your password in single quotes, or - if your password itself contained single quotes - failed to properly escape them.
The wireless password must be between 8 and 63 characters long if it is in ASCII notation. A 64 character password is allowed, but must be given in hexadecimal notation. So either 8 to 63 random characters or an exactly 64 character long hexadecimal string.
Note the special characters such as
$ ` ' "
may cause problems when improperly escaped.
When setting the password
special " character ` password $ test ' string
via the gui, the following notation will end up in /etc/config/wireless
:
option key 'special " character ` password $ test '\'' string'
Note how the special '
character got escaped.