because NTFS is a closed format (owned by m$) and it's only available reverse engineered by some people i would say: yes, definately.

the native format for the n900 would be ext3.
(it's open and there is a driver for windows too -> http://www.fs-driver.org/faq.html#acc_ext3)

but you can also format your card with fat32.
then you wouldn't have to install drivers on your windows computer.
edit: maximum file-size about 4gb!

choice is yours.