Hi ncaasportsoutlet,
Thanks for posting about your experience here. We actually have tools available that should allow you to revise the "Duration" field in both active listings and saved listings in bulk, and I am not aware of any known issues that would prevent you from making those revisions. I would have hoped the error messages generated would have explained the problem but I assume from your message that was not the case.
In any event, if you are still in need of assistance with this problem, please contact our customer support team by mousing over the "Help" tab within your account and sellecting the "File Support Case" option and we will do our best to assist you.
-Mike