Luckily for you, high X.org CPU usage doesn't mean you have a bug in X, so this problem is likely something you can solve.
X is a server, which means it responds to client requests. If a client has lost its mind and is making excessive X calls (such as if it locks itself into a graphics updating loop), it can make a lot of X calls. This shows up as a high X CPU load.
So, the thing to look for is to identify which client program is causing the load. Often it is a program you don't realize is even running - perhaps a panel indicator or background task or service. Look through your process table for user processes that look out of place, and try killing them one by one until the load goes down. Then you know what caused it.
Alternatively, log into a guest account; verify the load is normal there. Compare your processes in the guest account with those in your regular account, and go from there.
While high X cpu bugs are not at all unusual, I have not seen many reported in oneiric, so I might guess that the faulty process is some unusual program not installed by default; perhaps something you manually installed previously that got automatically upgraded to a new version that has a bug in it? Anyway, good luck in your hunt.
As suggested by Cedric Julien in the comments,
To view all the processes that are using CPU, when using System Monitor, go to the View menu and select All Processes
Best Answer
Long Answer
The General Python FAQ states:
In this context, there are 3 important facets: (Bolded)
Why This is Important
All Linux'es main method of doing things, irrespective of the Window or Desktop Environment is the terminal, commonly called the TTY. Since the main method of input into the TTY is the keyboard, scripting became the main method of automating things, and while there are plenty of native scripting tools on Linux, like Awk/gAwk and Sed, some like Awk and Sed, are sometimes challenging for beginning scriptors, and challenging syntactically for even experts.
Since Python is a scripting language, it can be used in place of the tedious tools like those I noted. The OOP part comes in handy, as I can use the methods of the language, instead of having to write sed or awk snippets over and over again. And that is what most modern Linux'es have done to ease development, and scripting among developers. One of your programs is using some python script, and is hung.
Short Answer
Knowing that python is a scripting language means that @mikewhatever and I are correct in telling you that your system is running a program that is invoking a python script, and the script is taking a long time to execute or is hung. Tools like
top
,htop
, and system monitor will tell you the name of the running script, and possibly the parent program that invoked the script.