Never noticed this before: 'Channel mixer' and 'apply image' weird behavior...

Hi,
Been using Photoshop eversince v5 and never noticed this before. So I figured I'd post here to find out if it's me going crazy or if the following is not normal behavior:
-When using a channel mixer adjustement layer to 'apply' a channel to a layer, the resulting layer is darker than the channel it's supposed to copy. Same when using 'apply image' and applying a channel.

For instance, if I have a layer, and decide I wanna apply the luminosity values of the red channel to it, I use a 'channel mixer' adjustement layer set to 'red filter', and the resulting layer should be an exact copy of the red channel, (which I can then set to 'luminosity' blend mode to achieve the intended effect). BUT the channel mixer results are not an exact copy of the red channel, it creates a darker version of it...

What gives?

(thanx for any feedback___very important for my sanity____ :-) )

Mikael Couderc
EnImages Multimedia