I'm having the same problem. So is it completely unusable with Win98?

Darn, and here I thought I was finally going to get to play these games with sound... :(

there is an alpha version for win98
http://vogons.zetafleet.com/viewtopic.php?t=900

You should be able to set up your sound card to work properly in Win98 for DOS games. Also you should be able to make it work with DOS-Mode shortcuts. (There is a topic on this in one of the sections, where I explained how to properly set up Win98 to play old DOS games)

what section and whats the topic name

Here, in the "Look Here First" thread pinned up on this page.

Look at the quoted guide in the second post.