Leopard not recognizing files

I just got a new power mac at work with OSX 10.5 leopard. I am a designer, and we have all our files on a server. The most important of which are quark documents. But any file that does not have a visible extension (.jpg .eps .psd etc...) that was created on another machine finder will not recognize nor will it let me open the file through the application that I know it goes to. It just tries to open it in terminal. HELP!! I saved a quark document from the new computer to the server and it did not have a visible extension but finder recognized it and let me open it. On my old machine I accessed this same file on the server and it only recognized it as a text file but did let me open it through quark. I'm kind of at a loss.

What version? From this link Leopaqrd requires version 7.31:-

http://www.quark.com/products/interactivedesigner/QID_102_update.html

An updater is included in the link.

for anyone who is interested this is what our mac guy said:

"I’ve seen the problem before....The problem is the formatting of the hard drives on the server and old files on the mac. The server loses the extension, but you can manually add the extension to open the file. No solution that I know of other than adding the extension manually."

adding the .qxd extension will fix this otherwise OS X thinks its a unix file