portability of datafiles

Hi!

I am developing a simple HR app. I decided to implement it with
postgresql and apache. I have both linux and w2k on my box,
but wanted to be able to develop independently from OS.
So, I have an idea, and I'd like to ask you to verify it's logic
and possible.

1. I have a FAT32 partition, which is r/w accessible from both OSes.
2. I have same version of postgres installed on linux and on w2k
(with cygwin support).
3. I have PGDATA set to same directory on the 'shared' disk.

Q.: Can I access my databases no matter which os I currently use?

Or, if not, is it possible to easily patch postgres to ensure binary
compatibility of datafiles beetween different systems at least on
the same hardware platform (like Linux end Windows on same PC)?

TIA,

Mariusz