Question about upgrading iTunes multiple computers with shared library

Greetings,

I have a question about upgrading to the current version of iTunes.

Currently, my household uses 3 Mac computers (2 Powerbook 17in laptops and a Mack Mini). We are all (currently) on system 10.4.11 (with iTunes 9.2.1). Between the 3 computers we have a shared iTunes music and video library on a networked high capacity hard drive.

We recently purchased an iPad. In order to make it easy for updates and to use media from our iTunes shared library I decided that we should upgrade the systems on our home computers to Snow Leopard. I have ensured that all the computers have at lease 2 Gb of RAM and adequate hard drive space.

The only possible problem I see is that one of the Powerbook laptops uses the old Motorola processor. (This is one of the last Powerbooks to use that processor.) I don’t think this computer can be upgraded to Snow Leopard.

My question is, if I upgrade 2 of the computers (and iTunes in the process), will I still be able to access the shared iTunes library using the older computer with the older system and iTunes? Will the upgrade process change the iTunes library in such a way that the one older computer will no longer be able to properly access that library?

Are there any other problems I might encounter having a mixed system/iTunes environment?

Thank you,

Tim