Hello Armando
I would suggest that you first check if those items (that you mention to be the "old entries") appear in case the user goes to the R/3 back end system directly, and access SBWP transaction (workflow inbox).
In case the items also don't appear there, then it's a problem from workflow perspective.
Moreover, it can be the case that the tasks are not displaying because of a custom XML file that is filtering the items, or either due to the iView which you using to access the UWL.
So please try to access through the UWL Standard iView. You can open it by launching the following URL:
Just change "server" and "port" by your portal corresponding values.
Also verify if any custom XML file is being used. In that case, remove the file and check if the problem still happens. You can check the XML being used through the UWL Support Information, which is documented on SAP KBA 1532883.
With kind regards,
Armando Zaro