I had an interesting phone conversation with eBay disputes, and discovered that feedback left by buyers can be removed without just cause.
With that said, I was also informed that though the feedback left was both legitimate and appropriate with eBay's policies, and it was removed and can no longer be changed.
When I asked why this happened, the eBay representative was unable to provide an answer.
Having said all that, it has come to my attention that eBay does not adheres to the service standard they ask of their customers - by asking customers to voice their opinions only to have these removed shortly there after.
PS. in the event that some of you feel this may be due to inappropriate feedback, I would add that the feedback was written and provided under the advisement of an eBay representative - and that it was completely legitimate.