### save command in SAGE

I'm trying to save a 'big' rational matrix in SAGE, but I'm running into problems.
After computing my matrix A, which has size 5 x 10,000 and each entry contains rational numbers in fraction form with total number of digits for numerator and denominator more than 10 pages, I run the following command:
save(A, DATA + 'A').
This gives me the following error message:

Traceback(most recent call last):
...
RuntimeError: Segmentation fault.

After this, I can't access A at all any more. In other words, when I try to compute say A[2,3], I get an error. However, before running the save command I was able to compute this entry. Also, I tried the same save command with a 'smaller' matrix and that worked fine. I should also note that I'm using a laptop with 64-bit operating system, x64-based processor, Windows 8, i7 CPU @ 2.40 GHz and 8 GB RAM. Let me know if you need further information. My questions are:
1. Why can't I save my matrix? Why do I get the above error message? What does it mean?
2. How can I save my matrix A? Is there any other way I can save it?