we installed 3.3 and it worked fine in the test environment (with a few users). we then proceeded to add more users and the problem started.
We also tried upgrading to version 3.4.0 (the version we're on now) but that didn't help.
I checked the work-around you suggested however the version in the systems table shows correct as 3.4.0 for us. (post upgrade). I also tried changing it to 3.1.0 to see if it makes a difference but it didn't.
Any other suggestions? or debug we could be running to get more info?