I complete agree with Weedpacket. There are so many different resolutions, browsers, opearting systems, etc. out there that it's too hard to predict exactly how a page will behave like that.
A possible solution would be to splice up your background image and just use a table with cells placed where the text needs to be.
Some of the above solutions may be easier, depends on the software you use, how much prior experience you've had with the types of solutions above, etc. etc.