audacity freezes/greys out on pushing STOP recording button

To duplicate problem... attach Line in to back panel. Set Audacity to record from line in. turn on : show clipping and software playthrough. Start recording ... continue for several minutes... sometimes seconds can be enough. Push STOP button. Wait a few seconds and screen will turn GREY and all functions will get locked out except for the MENU at the top of the screen which will show all options but will not allow selection of any options or actions.

Only solution is to force quit the application. After which on the subsequent restart Audacity advises the application was not closed properly and offers to save the temporary file it has recovered with the recording.

Problem repeats on the next recording attempt. Audacity was installed from the Ubuntu Software Centre.

I expected that I could stop recording and then play back the passage and edit it... eventually saving it.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: audacity 2.0.5-2ubuntu2
ProcVersionSignature: Ubuntu 3.16.0-30.40-generic 3.16.7-ckt3
Uname: Linux 3.16.0-30-generic i686
AlsaCards:
 0 [SI7012 ]: ICH - SiS SI7012
                       SiS SI7012 with ALC658D at irq 18
ApportVersion: 2.14.7-0ubuntu8.1
Architecture: i386
CurrentDesktop: Unity
Date: Sun Feb 15 15:16:50 2015
ExecutablePath: /usr/bin/audacity
InstallationDate: Installed on 2015-02-15 (0 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release i386 (20141022.1)
ProcEnviron:
 PATH=(custom, no user)
 LANGUAGE=en_CA:en
 XDG_RUNTIME_DIR=<set>
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
SourcePackage: audacity
UpgradeStatus: No upgrade log present (probably fresh install)