Illustrator :: CS5 / Random Crashes When Saving Or Previewing Work

I tend to get errors when I save my work in Illustrator. A few read as follows:
 
"Unknown Error"
"Can't Save Illustration"
"Not Enough Ram Available"
 
The last error I got read: "Can't finish previewing. There is not enough memory ID = -108" These errors don't happen all the time, but they occur often. And when they do occur, more often than not end up crashing Illustrator and can't save whatever I just worked on.

Here's what I've tried doing:

Cleared my Illustrator preferencesUninstall the whole Aodbe Suite > Run the Adobe Remover Tool > Reinstall Adobe SuiteRun disk clean up/defragmenterI get some of these errors even when I only have Illustrator and my browser open - no other programs are running except for anti-virus/malware software. 

Here's some trivial information about my machine and the file I'm working on:
 
RAM: 4GBThe file I'm trying to edit is 0.97MB and stored locally on my desktop (as opposed to a network drive)Graphics Card: Nvidia GeForce 8400GS (up-to-date)Hard drive has 231GB of free space64-bit processorRuns DirectX 11