After Effects error: unable to allocate space for a 2200 x 1465 image buffer.

Hi guys:

I'm a newbie to AE. I bought Riot Gear and Evolution from VideoCoPilot and I made some projects of my own. Here's the problem: As I export, through Render Queue, a Composition only having Riot Gear stuffs, in low resolution, everything is perfect. However, all my Evolution Compositions, in high definitions, are currently expecting this problem as I export through Render Queue:

After Effects error: unable to allocate space for a 2200 x 1465 image buffer.
You may be experiencing fragmentation. In the Memory & Cache Preferences dialog box, try decreasing the Maximum RAM Cache Size value and selecting the Enable Disk Cache option, increasing Maximum Memory Usage, or both.

Here's what I've done so far: I format the disk, I played around with the Maximum Memory Usage and I have used 15000MB for disk cache...

It doesn't work =_______________________=

I have 2GB of RAM and over 70GB of disk space for this tiny project... What can I do?

Help~~~ T_T