Folks, negative feedback is your friend. It encourages honest trades and protects those who would later consider trading with this individual. Since she/he/whatever has had problems at least dating back to july (tarkus) then there should be negative feedback on the profile to warn others off, especially when comms are not responded to or ignored. I can see giving someone a couple weeks, but if it goes past 3 I'd be on them, especially if they claimed they shipped it already.
Its the sellers responsibility to keep the buyer up to date, to supply tracking information and to resolve problems if there is a shipping problem. Its also their responsibility to stay hot on the comms to ensure problems get resolved. There is NO excuse for 2 weeks of no comms when in the middle of a transaction. Its irresponsible as a seller. Not having given someone their product since July is a downright rip off.