Facebook android help?

[Jabuuty]

For your username, try using your whole email address
for the password, make sure it's not capitalized or lowercased where it's not supposed to. (i think Facebooks passwords are case-sensitive)
Try logging in from the phones browser and the Facebook App from the market.
If both don't work, then there must be a bigger problem. If you don't have the Facebook App, download it .... from the market.