Load and Performance testing using jMeter, not able to edit-delete during test

Has anyone ever try this and been successful?  our company has a manidate to load test and am not able to complete it as of date.

Basically, I’m not able to get the script to perform some operations (delete project, add project details) that I can do in the UI manually. 

The system gives the same responses to the calls that I see in my proxies when I perform the operations manually (i.e. no errors, same acknowledgement message) but the operation doesn’t “stick”.

It seems as if something downstream must be rejecting my calls after the app server accepts them, but I’m not sure why.