Hope this can help...
http://audacityteam.org/wiki/index.php?title=Mixer_Toolbar_Issues#Linux-specific_issues
*Linux-specific issues*
- *Input Selector and Input/Output level sliders missing*
If Audacity's entire Mixer Toolbar (i.e. the input and input level sliders
and the input selector) is
Public bug reported:
Binary package hint: audacity
On a fresh install of Kubuntu 7.04 with Audacity 1.2.6-0ubuntu1 the
input selector is missing from the toolbar thus making it impossible to
record from other audio feeds then MIC. Audacity recommends that the
package is rebuilt. I have never
