Intel Mac mini - maximum RAM Upgrade

I have a Mac mini with a Core 2 Duo processor (2.4 Ghz). I plan to upgrade the RAM in my Mac mini. Currently, it has 2GB right now, 1GB per slot (2 slots total). I would like to buy a new 4GB for a single slot.

This means I would have 4GB in one slot and 1GB in the other slot. I have heard that 32-bit OSes don't support more than 4GB of RAM. Is it the same case here?

To find out the architecture of my Mac OS, I used this command:

uname -p

It shows i386, it means Mac OS X is running 32-bit operating system. Will there be any problem while upgrading RAM?

Summarizing My Question

What is the maximum RAM supported in this Mac mini? (Mac mini 4,1 - new version of Mac mini) Will OS architecture be a constraint while upgrading RAM? Is this constraint applicable to my current case? How?

For starters, OS X doesn't have the silly 64/32-bit dichotomy that Windows and Linux do. For most purposes, you can consider recent versions of OS X to be both 32- and 64-bit at the same time. The limiting factor in almost all cases of upgrading Mac RAM is the hardware chipset.

For your Mac mini 4,1: my copy of Mactracker says that the maximum RAM is 8GB. Your five-gig setup should work fine.