This fact should have automatically barred Diebold from being certified, but evidently the accreditation organizations don't consider accurate vote counting as essential to certification.
All this has been brought to light by Debra Bowen in CA and could lead to Diebold's decertification in CA and hopefully in other states as well. In fact, since I'm just hoping, here's wishing them a total lack of certification in every state and municipality in every square inch of the US.
Here's Bradblog's story:

Startling admission made during public hearing in CA to consider decertification of the company's voting and tabulation software...
by Mitch Trachtenburg
Even the audit log system on current versions of Premier Election Solutions' (formerly Diebold's) electronic voting and tabulating systems --- used in some 34 states across the nation --- fail to record the wholesale deletion of ballots. Even when ballots are deleted on the same day as an election. That's the shocking admission heard today from Justin Bales, Premier's Western Region manager, at a State of California public hearing on the possible decertification of Diebold/Premier's tabulator system, GEMS v. 1.18.19.
An election system's audit logs are meant to record all activity during the system's actual counting of ballots, so that later examiners may determine, with certainty, whether any fraudulent or mistaken activity had occurred during the count. Diebold's software fails to do that, as has recently been discovered by Election Integrity advocates in Humboldt County, CA, and then confirmed by the CA Secretary of State. The flaws, built into the system for more than a decade, are in serious violation of federal voting system certification standards.
The problems may lead to decertification of the company's voting systems, as well as an examination of voting systems made by other companies to determine if they too may have been able to sneak such violations past both federal and state testers...
Here's the rest of the story:
http://www.bradblog.com/?p=6995#more-6995