Could not create language plugin for C++.

[Yang]

I'm using manually-built KDevelop 3.4.1 on apt-installed KDE 3.5.6 on
Ubuntu Feisty, I get "Could not create language plugin for C++." when
trying to start a new project. On the console, I see:

kdevelop (core): Looking for language support for C++
X Error: BadDevice, invalid or uninitialized input device 169
  Major opcode:  145
  Minor opcode:  3
  Resource id:  0x0
Failed to open device
X Error: BadDevice, invalid or uninitialized input device 169
  Major opcode:  145
  Minor opcode:  3
  Resource id:  0x0
Failed to open device
Launched ok, pid = 9089

I checked the ML and found:

http://lists.kde.org/?l=kdevelop&m=107936550012043&w=2

However, ldd shows that libdb is being found for that library (also
all other libraries are listed as found).

Thanks in advance for any help.

Yang