Apple wireless keybrd: bluetooth dont pair anymore

[ovalf]

During months I work (in love) with my apple alluminium wireless keyboard.
My cheap batteries go down and I update to 10.5.7.
I need to re-pair (bluetoot unit), the Assistent see it, so I put a code via other usb keyboard or auto-create, I put the code via bluetooth, the under windows shows yes to connect and pair, and BUM!
I am with 10.5.6.3 kernell, tested a lot of diferent kexts, clean all bluetooth from preferences, repair perm 9 (etc) and nothing make a diference.
I am searching A LOT and this problem is common too in real Macs.
My bluetooth (usb) dongle seams to work OK.
Any suggestion will be apreciate - sorry for the english.
Thanks in advance.