Add to Lookup Field Bug

Add to Lookup Field Bug

In my application there is the Task View or the Add_Task form, when someone adds a new task, there is an issue when someone attempts to add a new item to the lookup field in the form.

In the add form, there are several lookup fields along with the Add To beside the field in case you need to add an option to the list.  When someone is in the process of adding a task, and needs to add something to the lookup field an error message pops up that says an error has occurred, however the item you just added to the lookup field is there.  But why is the error message popping up and how do I get rid of it?