Plesk autoupdate failure report 7.5.3 -> 7.5.4

[atrocity]

Hello,
I try to update our Plesk server (7.5.3 RHEL3) to 7.5.4, but i receive this error message at the end of the failure email :
Preparing for packages installation...
----- begin of output -----
Installing mysql-server-3.23.58-1.i386.rpm
Installing mysql-3.23.58-16.RHEL3.1.i386.rpm
file /usr/bin/comp_err from install of mysql-3.23.58-16.RHEL3.1 conflicts with file from package MySQL-devel-4.0.24-0
file /usr/bin/mysql_config from install of mysql-3.23.58-16.RHEL3.1 conflicts with file from package MySQL-devel-4.0.24-0

----- end of output -----

I have installed MySQL-4.0.24, and now Plek refuse to update ...
What should i have to do ?
Uninstall MySQL 4.0.24 ?
Uninstall MySQL-devel ?
If the anser is yes, what's about the sites using MySQL ? We have a very lage and popular forum on this server ...
Many thanks for any help.
Best regards
Jean