Preview of eps files strored on win 2003 server from mac os x

Can someone please suggest a solution? We use Windows 2003 server as a file
server for mac clients and PCs. An eps file created using illustrator and
stored (on server) with Macintosh preview (instead of TIFF preview) is not
displayed when opened from another mac through QuarkXpress. If the same file
is stored on another mac and opened from any other mac, the preview can be
seen properly and the file displayed properly after 'Insert'.

To make it a bit clearer: When creating a new document in Quark and
inserting a picture (the eps picture stored on the server), the 'browse'
dialog on mac shows a preview of the eps. In our case, the preview is not
available.

As mentioned earlier, this problem occurs only when the file is stored on
the Win 2003 server and not on another mac.

Many thanks.