Update 8.1.1 -> 8.6 after I have already upgraded to mysql5 and php5

[Sam Bondareff]

Hi I have a VPS with Plesk 8.1.1 installed on Centos 4.2 OS. I have upgraded my mysql4 and php4 through yum to versions php5 and mysql5. I was wondering what adverse effects I would have trying to update Plesk to 8.6 or 9.x knowing that I have made these changes manually to my system.