Yes, I tried that: it still fails even when told to use the full Gig. Even if that was the problem, the fact the same script (with the same data) on Linux requires only 43 MBytes would suggest something is wrong (or at least different) on Cygwin.
--Dave Opinions my own; statements of fact may be in error.
Comment on Re^2: Storable, Cygwin, and memory issues
In my rush to actually try to contribute something useful, I failed to fully read your original post, and totally missed the part where you upped the memory limit. My earlier comment should be downvoted. Sorry about that.
Unfortunately, I have no insight into why you're running out of memory...