Menu not displaying correctly in 3.0

I updated the theme Adventurous Free from 2.2 to 3.0. Now the menu at the top of each page does not display correctly. I have Menu1 set to be the menu. Previously it displayed across the top of the screen with the various menu entries. Some of them are drop down child menus. Now the menu is represented by 3 lines on the right of the screen. Clicking the 3 line button creates a large screen-filling window with a whole bunch of entries in a list down the left side of the window. It appears to be placing every page in the system into the menu, not the entries specified in Menu1. I tried a bunch of things to get it changed back, with no success. Is this a permanent change? If so, I will need to find a new theme. Thanks, brew