I have recently ported a Joomla custom extension to 3.3.x that I originally wrote for 1.3 and have had running on 2.x for many years.
It is a standard extension that presents a list of records that show various fields for each record. The user clicks on one and a form showing the listed fields and others. User updates values and clicks Save and Close. The record saves correctly, but the browser does not refresh the previous page but simply re-displays the original. The consequence is that User thinks it hasn't worked, clicks on said record a second time and brings up form with correct (as in updated in first attempt) values. The now frustrated user blames programmer.
For very good and unavoidable reasons, at the same time I ported the site to Joomla 3.3, I also had to move from an in-house managed server to a Zen hosted one. I have several other clients on Zen and have not experienced this problem, so I suspect my user is right to blame the programmer.
I can't find anything relating to caching and custom extensions and the site setting for cache is OFF. The template uses the JAT3 plugin, but has done so for at least four years. There was an update to this as part of the Joomla upgrade.