Ubuntu不要升到11.10

今天手癢把系統升級到11.10，執行nam的時候出現以下錯誤訊息：

nam:

[code omitted because of length]

: version conflict for package "Tcl": have 8.5.10, need exactly 8.4

    while executing

"package require -exact Tcl 8.4"

老實說我找了好幾篇解決方案，講的都是同一招，而且我還看不懂，擷取其中最後一段：

OK, you have the library, so your executable is not looking in the right place for
 it. To list the libraries an executable needs, run the command: ldd executable
Look at the tcl8.4 in the list -- should not have an explicit location, just a name
, so it would get picked up from a normal library search. If it has an explicit loc
ation, and the location does not have the library, put the link there to the tcl8,4.

  If you installed the executable from an Ubuntu package, then report as a bug. If 
you downloaded from a ramdom location on the internet, then this is the sort of pro
blem you'd expect. You can rebuild it yourself, or add the links to your system to 
make these sort of things work. 

不懂其中ldd是什麼指令，還有executable是代表什麼意思，所以就先不要升級吧！