`Transfer` is an event, `transfer` is a function. This [0] is from TheDAO attack and is one of the (many) bugs making the attack so terrible.

As for name mangling, read this [1] and see if it seems sane to you.

For bonus points [2], `this.foo()` and `foo()` mean two wildly different things.

I don't even know what they were thinking.

[0] http://vessenes.com/deconstructing-thedao-attack-a-brief-cod...

[1] http://solidity.readthedocs.io/en/latest/abi-spec.html#

[2] https://github.com/ethereum/solidity/issues/583