Dear Christopher,

Following Hanchuan's suggestions, I just updated my Ubuntu system to 11.04 and also checked out the newest code. Now I have no problem building the latest version (svn r2700). I don't know if it is because of your revision or the new system. But for those encountering such problems, an Ubuntu 11.x system with r2700 will certainly be a solution.

Thanks a lot for your help!

Yinan