Upgrading MySQL from 3.28 to 5.0.20

[sushestvo]

Alright, my server has 99% CPU loaded by mysqld all the time unfortenetely. Everyone tells me I need to upgrade mysql and it would really help my server's performance, Plus you can tweak 5.xx better.
So I decided to upgrade =)
Hopefully someone can help me do that w/o loosing my MySQL Data =)
Current system:
OS: Fedora Core 3
PHP 5.1.2
ISPConfig 2.2.1
Looking for some easy way to upgrade.... apt-get didn't work. Says there is nothing to upgrade... actually didn't want to update my PHP either... I went through hell upgrading this a month ago.
So I found some RPMs: http://remi.collet.free.fr/index.php...4-mysql-5020-1
Well... should be easy to upgrade with yum? right? well, no, gave me an error:

[root@fc3 ~]# yum --enablerepo=remi update mysql\*                                    
Traceback (most recent call last):
  File "/usr/bin/yum", line 7, in ?
    yummain.main(sys.argv[1:])
  File "/usr/share/yum-cli/yummain.py", line 34, in main
    locale.setlocale(locale.LC_ALL, '')
  File "/usr/lib/python2.3/locale.py", line 381, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting

yeah, btw, how do I change my default sys locale back to en_US? =) lol

surely, there is always an option to wipe out MySQL 3.xx rpms... and then install 5.0.20 Rpms... but is there a better way? I'm just really afraid to screw system up. It's a production server. Hope someone can help.

[sushestvo]

ok, guys never mind =)
got everything upgraded and it works nicely =))))

[sushestvo]

now i have huge problem. I hope someone can help.
After upgrade went through - site still works with MySQL.
But some functions stopped working. For example I have a function to edit desription for items on the web-site, well, I can't edit it any longer.
I took mysql query directly into phpmyadmin and got this:

#126 - Incorrect key file for table './web4_db1/table.MYI'; try to repair it

repairing it doesn't help. What happened? Help!