Hi,
I would first check the Linux install instructions, as there are significant differences between Linux 12.04 and 10.04.
http://processors.wiki.ti.com/index.php/Linux_Host_Support
http://processors.wiki.ti.com/index.php/Checking_Linux_Dependencies_for_CCS
If you installed CCS after updating your OS, then I think most of the potential issues with missing libraries (as shown in the above pages) would have been covered. If not, I would potentially reinstall CCS and see if by any chance a library is missing and is causing the connection issues.
Actually, I would install a newer release of CCSv5 (5.5) or even CCSv6, as support for Linux improved a lot since CCSv5.2 was released. You can even install it in a different directory and use a different workspace to compare the two.
The error message you are getting is indicative of the failure in initializing drivers/recognizing the emulator by the system. A common error is the <install_drivers.sh> is not properly run at the end of the install, but it seems you already executed that utility.
To further debug this, try to run the xds100serial utility as mentioned in this thread. This will verify if the system is recognizing the emulator.
If the utility can't recognize the emulator, try to change the USB port as this usually makes Linux to re-enumerate the devices (and the device driver properly initializes).
If the utility can recognize it, try to run the Test Connection button from the Target Configuration Editor. This usually brings some additional insights to what may be happening.
I everything above is ok, I would try to connect manually to the target and see at what step the operation fails. Step 4 of the link below shows how to do this and several additional tips to troubleshoot this issue.
Hope this helps,
Rafael