I have the BBpress plugin working fine in my Shoutbox theme. I had to toggle the settings-permalinks-post name to default and then back to post name. I used the shortcode [bbp-forum-index] to place the forums on my wordpress forums page. I used the default template with the side bar which makes the real estate available for BBpress somewhat small, but also leaves room for the login widget in the sidebar. As the forum was somewhat truncated from not normally fitting into the small space available in the Shoutbox theme default template (with a sidebar) I added the following css to the top of the bbpress.css
img {
border: medium none;
display: inline;
margin: 0;
padding: 0;
}
.entry-content ul li {
list-style-position: outside;
list-style-type: disc;
margin-left: 0px;
padding: 2px 0;
}
.bbp-topic-freshness {
font-size: 11px; /* size of font for freshness */
}
This makes the default theme for bbpress play nice with the amount of space Shoutbox offers.
You can also add the following css which removes the Name of the poster on the forum page and makes things cleaner in my estimation.
.bbp-topic-meta {
display:none;
}