It took ages and effort to get Kdenlive work in the first place. Now having paused for ~4 weeks and wanting to continue I am stuck agin ... trying to Add Clip gives the error message "FAILED TO CREATE PROXY CLIP":
ffmpeg version 0.8.4-4:0.8.4-0ubuntu0.12.04.1, Copyright (c) 2000-2012 the Libav developers built on Nov 6 2012 16:51:33 with gcc 4.6.3
*** THIS PROGRAM IS DEPRECATED ***
This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
Input #0, mpegts, from '/home/hlan/Desktop/Cameoscope/PRIVATE/AVCHD/BDMV/STREAM/00000.MTS':
Duration: 00:00:48.97, start: 0.801678, bitrate: 25075 kb/s
Program 1
Stream #0.0[0x1011]: Video: h264 (High), yuv420p, 1920x1080 [PAR 1:1 DAR 16:9], 50 fps, 50 tbr, 90k tbn, 100 tbc
Stream #0.1[0x1100]: Audio: ac3, 48000 Hz, stereo, s16, 256 kb/s
Stream #0.2[0x1200]: Subtitle: pgssub
Unknown encoder 'libmp3lame'
In the log we see that ffmpeg is rather recent (6 Nov 2012) and the problem is perhaps related to a Package Manager software update? At the end it says "unknown decode libmp3lame" therefore perhaps this issue can get fixed by just finding libmp3lame package and installing it - but before I mess things up even more, does anybody know what happened and any advise about fixing this issue?
Thank you very much in advance...

1) libmp3lame is installed and re-installing did not fix this problem. Maybe something happened to ffmpeg (that apparently requires the library to be enabled at the time when ffmpeg is installed? How can I re-install ffmpeg with all the whistles and bells that it requires to work for Kdenlive?
2) At the moment my Kdenlive encoding profile for proxies is the default:
-f mpegts -acodec libmp3lame -ac 2 -ab 128k -ar 48000 -vcodec mpeg2video -g 5 -deinterlace -s 480x270 -vb 400k
What would be a simpler and more robust profile to use?
Thank you very much in advance,
hlan (worried about what else with Kdenlive may have auto-destroyed itself...)