I've used/loved this function for years, but something's going wrong for me tonight. Also the first time I've used it with MatLab 2014b (64bit).

With x values of [1:4], errorbar_tick is moving my 4th point over to an x-value of .08, so the updated series of x values becomes [1 2 3 .08]. I'm totally boggled. Any ideas?

Works great. For a graph with many errorbar plots this works:
>> h = get(gca,'Children');
>> % h is an array of plot handles
>> errorbar_tick(h(n),200); % etc.