It is hard to reply to your query as it does not give us specifics about system, hardware, software, updates, fonts. plug ins, etc.
What do you need to know about the Fonts??
The Screen preview breaks up while working on files....Need to restart the program.
When saving files....Does work properly..
Sometimes "Exporting into JPG" doesnt work either!
Then while a Large file is Open...and I have another file open...I cant "save" becuz I get the "Not enough RAM" error....I must close out the other file to save the one I need.
There are NO updates.....I loooked the last one was from 2009 in Feb.
I don't think I can help you with this type of information.
Perhaps someone else will take a crack it.
I will guess with the little information you gave us that you simple do not have the resources to work on files that are that large.
The 3GB of Memory is a good indication that your resources are limited. You have to keep in mind that one of the features of AI is unlimited undos that requires after short while on a large project a lot of free continuos space on a scratch disk separate from the start up disk. Having 3GB of RAM might seem like a lot to you but it is not a lot if you are running other programs, a browser and the OS.
The developers tell you you can run these programs and os on such an such amount of RAM, which is true to some degree. Beyond that degree you will have crashes because the resources become strained and the cache build up chokes the data flow so stuff hangs waiting for the data to flow which happens very slow because of the bottle neck and then sometimes just stops.
Fonts often overrun the data base if they are not made well like many free fonts.
I you tell us about your system we might be able to help you pin it down and you might be able to fix it. You might not be able to it may be the files are to big and complex for Illustrator, itis hard to tell from the little information you have told us.
Tell us about what you have and you will get more responses. Do you have any plug ins etc, how many disk? Some information.
I see you answered the plug in question the at was an auto response. I will qualify it how about third party software etc?