Fedora Core 5: Don't know how to get changed the max size (1GB) of file in Edit --> Preferences -->Preview

[Hilkka Outinen <hilkka outinen kolumbus fi>]

Hi,
Would anybody advice me how to get the max limit for file sizes changed 
in Edit --> Preferences --> Preview. The value list shows 1 GB to be the
max size I can use. I would need more than this.
Neither can find this information in the documentation.

Thank you,
Hilkka