Here's my exact error:

root@bt:/pentest/exploits/framework3# ./msfconsole

(I removed the fancy metaploit text for this post)

       =[ msf v3.3-dev
+ -- --=[ 345 exploits - 223 payloads
+ -- --=[ 20 encoders - 7 nops
       =[ 123 aux

msf > load db_mysql
[*] Successfully loaded plugin: db_mysql

msf > db_create

mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' (using password: NO)'
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)[*] Database creation complete (check for errors)

msf > db_import_nmap_xml xpsp2.xml
[-] Error while running command db_import_nmap_xml: Access denied for user 'root'@'localhost' (using password: NO)
I've tried this with a regular user also and I get an access denied error message.

I was trying to get metasploit running on ubuntu 8.0 and was having some of the same difficulties. I did have metasploit working properly earlier, but only after running:

dpkg-reconfigure mysql-server-5.0
Is there a better fix to this error rather than reconfiguring mysql everytime?