For instance, on the Netscape Net Search: Infoseek Guide main page there are four frames. One across the top of the page (a header), one across the bottom (a footer) and two side-by-side frames sandwhiched between the header and footer.
Both of the two frames that are the middle of the sandwhich have vertical scroll bars. We were able to get into the first frame, scroll down the frame and read all that was included in it. Then we could down arrow to the next frame, but could not scroll down as we had before.
Another anomoly that we have found and are unable to determine if it is a problem with the screen reader or with the browser, is that the first time into the first vertical frame we were able to use the page-down key to page through the frame. However, we were only able to do this the first time in the frame. Even after leaving the page and returning, we were unable to reproduce this action.