I got a bit freaked out and just rebuuilt it back to 4.x.x I'll try again tonight (during non busy eriods) and i'll copy paste the error but it mentioned a uncompatability with the mysql i have installed
Its due to mysqli, It seems there are certain versions of mysql that will allow the upgrade work fine. I usually downgrade to mysql 4.1.13 first and then you can compile any apache config you like without trouble.