Changing individual Tick labels

Dear all,

None of the obvious ways for changing ticklabels seem to work for the current version of Matplotlib (1.2.0 for me). At present, ax.yaxis.get_ticklabels().get_text() returns empty strings, as does ax.get_yticklabels(), and the equivalent set_* functions don't seem to have any effect.

So: help!

Yours,

Andrew