Pop up window saying Memory is too low to continue in Logic.Why?Way to Fix?

Question

I recently purchased my IMac OSX 10.6.3 as well as Logic. I have about a half dozen projects on my hard drive now, which is also being backed up to a "time machine" external drive. The projects are pretty small( just piano, or piano and string quartet, etc.) I also just installed Office Suite for Mac and the full Adobe Creative Suite.
Recently when I have been working in the Score Editor(In Logic Pro 9), a pop up window appears saying something to the effect of "memory is getting low, don't install more plugins and remove any unused ones." Then today, after that pop up, another one showed up and said "memory is too low to continue. we will close project, autosave, etc. etc."
Why is this happening? Is there not enough memory on my computer? Will this actually effect editing procedures in Logic? (because it seems like some things aren't working like they used to) Is there a quick and easy fix? Is this related to space remaining on hard drive, or is it completely different? Could it be related to the IMAC backing up files to my "time machine" drive at the same time I am working in LOGIC?
Could someone who has a little time on their hands please answer these questions IN DETAIL? I am new to MAC and LOGIC, so I really have no Idea what's going on with the memory issue. I don't even understand how MEMORY corresponds to available space, quality of running programs, etc.
Please help. I'm working on a deadline to finish a Master's portfolio and this could potentially be a big bump in the road for me.
Thanks....

Answer 1

The System Requirements for Logic Studio call for a minimum or 1 GB RAM with 2 GB recommended. So you should not have a problem with your 4 GB.
First make sure your RAM is being recognized by your computer. Go to Apple Menu (apple in upper left hard corner and click on "About this Mac". Make sure it say 4 GB. Ram chip at times will go bad or become unseated.
Now for troubleshooting, here is what I would do. The next time you want to use Logic, restart your computer. Restarting "flushes" the RAM; it may not sound like it but that is a good thing. Then do not open any other programs other than Logic (except ones you may need for it). You listed an awesome group of software you own. Your computer is not set up for all these programs to automatically start up when you turn on the computer, is it??
So I am betting that you will not get the low memory message when only Logic is working. With some trial and error you will be able to open more and more programs at the same time without effecting Logic.
You can better understand your RAM by opening Activity Monitor (Applications >> Utilities >> Activity Monitor). Click on the System Memory tab at the bottom and you can visualize what your RAM (Memory) is doing. There is also a list of programs that are open and what resources they are sucking up.
Good luck with your computer and your masters.
Arch