[support] Drupal weirdness, please help

[Krister Ekstrom]

Hello,
I'm helping a friend get started with her web site which we are planning
on creating in Drupal. She has a remote server using CPanel and
fantastico and it's through this that we have installed Drupal. When we
installed, nothing seemed to go wrong, it indicated that the
installation had gone all right but when we started enabling modules and
create user roles the following error message started to appear:
user warning: Got error 28 from storage engine query: SELECT DISTINCT
b.* FROM blocks
b LEFT JOIN blocks_roles r ON b.module = r.module AND b.delta = r.delta
WHERE b.theme
= 'garland' AND b.status = 1 AND (r.rid IN (2) OR r.rid IS NULL) ORDER
BY b.region,
b.weight, b.module in
/home/nanna/public_html/includes/database.mysql.inc on line
172.

After this we no longer can access administrative tasks and we can't do
anything else than read the newly created home page and the pages it
points to, but no user login or nothing. What could I/we have done
wrong? Do i have to uninstall the whole system and reinstall it again?
/Krister