Site with MySQL problem?!

[edge]

I’ve created a site account with a MySQL database (with the use of ISPconfig).
The database name is: web15_db1 and the database user is: web15_u1. (I also enabled the "remote" option, and did set a password.)

When I access the server with "phpMyAdmin" I do see the database and user name, so this is all working fine.

Anyway.. Today I tried installing "phpBB2 Plus" (it's a forum), but for some reason it did not accept the user/database name!
The error I was getting is Client does not support authentication protocol requested by server; consider upgrading MySQL client
(I'm 100% sure the username and passwor that I used was correct)

The strange thing was that when I deleted and recreated the same user and same database again within "phpMyAdmin", I was still getting the same error!

I've now setup the forum with the root MySQL user and password :/

Anyone here who might know what could be wrong?
Does MySQL not exept users or databases with a "_"??

MySQL version is MySQL 4.1.11-Debian_4sarge5

PS.. I will try to recreate the error on a new test site later today.

[edge]

Okay.. I found a fix..

Run mysql and login as root:
mysql -u root -p

mysql> SET PASSWORD FOR
    -> 'some_user'@'some_host' = OLD_PASSWORD('newpwd');

In my case the 'some_user' is web15_u1
The 'newpwd' is the password that you would like to use..

[falko]

Then phpBB seems to have a problem with MySQL 4.1 or something like that...