It’s hard to attribute the low scores to a one-time failure, presumably of relatively short duration, given the time span during which avast! 2014 has scored poorly:

Windows 8, Nov-Dec/2013
http://www.av-test.org/no_cache/en/tests/test-reports/?tx_avtestreports_pi1[report_no]=134923

Windows 7, Jan-Mar/2014
http://www.av-test.org/no_cache/en/tests/test-reports/?tx_avtestreports_pi1[report_no]=140613

These tests appear to span at least 3-4 months and use avast! 2014.

They show a marked decline in performance scores from earlier tests using prior versions.