When upgrading JOOMLA use the joomla utilities in CPANEL. We used to use ADMIN TOOLS but that no longer supports joomla 1.5 and all the other tools can be found in CPANEL joomla utilities.
When upgrading the core files the more+ links get broken – to fix them you need to:
263: READMORE=More +
264: READ MORE…=More +
You will also need to upload a new header graphic for the backend. Right click image to locate the files.