I turned-on the whitelist and added the following IDs in this order:

kvgeorge1
pixelb0x0rz
PufffNStufff
Dutchesss

When I reloaded the whitelist, I get the following response (note the case-sensitivity):

[INFO] There are 4 (out of 3 seen) whitelisted players:
[INFO] dutchesss, kvgeorge1, pixelb0x0rz and pufffnstufff

The text file still looks ok, but when I remove say, Dutchesss from the whitelist and reload, this player is STILL allowed to get on the server even when the /whitelist list command shows the following:

[INFO] There are 3 (out of 3 seen) whitelisted players:
[INFO] kvgeorge1, pixelb0x0rz and pufffnstufff

So, the whitelist functionality is not working as expected.