Python on 64-bit Windows Vista

[dineshv]

Does anyone have experience of working with Python and very large text
files (> 10Gb) on 64-bit Windows Vista?

The problem is that my Python program - to perform simple data
processing on the 10Gb file - never completes and ends with an error.
When I reduce the size of the file (< 5Gb) the program works
perfectly.  So, it is not my code!

This is not the first time that this has happened and I'm wondering
what is it about Python and/or 64-bit Vista that causes these
inexplicable errors when processing very large text files?

Dinesh