[SOLVED] Update to 1.11.1 > Undefined index: window_look_back_for_visitor & tracker_cache_file_ttl:(

(Somehow, the old 1.10 - global.ini.php was used for the new piwik 1.11 and caused that problem)

Since my update from piwik 1.10 to 1.11.1, I get lots of the following two errors in my apache error log:

[Thu Mar 14 23:04:55 2013] [error] [client XXX] PHP Notice: Undefined index: window_look_back_for_visitor in /xxx/piwik/core/Tracker/Visit.php on line 1329, referer: xxx
[Thu Mar 14 23:05:02 2013] [error] [client xxx] PHP Notice: Undefined index: tracker_cache_file_ttl in /xxx/piwik/core/Tracker/Cache.php on line 29, referer: xxx

Piwik seems to be working (I see no errors and the visitors seem to be counted correctly). I deleted the content of the tmp-folder, have restarted apache, … Nothing helps.

Any idea what is the problem?