About: http://webisa.webdatacommons.org/126039733

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Since we have to guess here, I would guess that the number you are passing in is a local that goes out of scope, so you are storing and trying to delete the address of an object that no longer exists.
http://www.w3.org/ns/prov#wasQuotedFrom	codeguru.com