optimizer cacher: not enough memory for adding cache

 
I'm getting this message in my strategy tester journal after optimizing for a while: "optimizer cacher: not enough memory for adding cache".

What does this mean and what do I need to fix it? I have a gig of memory so I don't think it means physical memory.
 
1. Download latest build 202, Feb 27. It is more efficient for memory usage.
2. Reduce testing period.
3. Change virtual memory settings.
4. Add physical memory.
Reason: