Stalk doesn't pull through all expected nicks

[Helzibah]

When stalk picks up a nick change, it doesn't always log both sides as expected.

I have a user who has changed from Foo to Bar and from Bar to Baz. Stalking Bar gets me:

Nicks: Bar (Changed nick from Foo to Bar)

and stalking Baz gets

Nicks: Baz (Changed nick from Bar to Baz)

I would expect the first example to at least contain Foo and the second to contain Bar as the nick change has clearly been picked up.