Also just from my own experience, I took the extra step of running the uninstall SQL for my add-ons before stepping through the upgrade process (the link DrByte posted). Since I was having to re-install all the add-ons from scratch anyway, I wanted to just bring forward a "cleaner" DB to upgrade. I found it made the add-on installs much cleaner later on..
Quote Originally Posted by CnTGifts View Post
Basically why i was asking is because i have addons on my current instal of 1.39 that some havent been upgraded yet.

So your saying i should overwrite all my files with the new 1.5 ones and then to the upgrade through zc_install?? And then just go on with installing the new add ons that are compatable?