Photoshop 7.0 and alpha mystery

My first repaint since installing Photoshop 7 and I've run into something very strange.Deciding to create my own master I followed my usual route. Open the bmp in imagetool, convert to 32 bit and save as a tga, thereby preserving the alpha. Open said tga in PS and save as a psd. Creation process begins.However, opening the tga in PS 7 I've lost the alpha and the image appears to have some kind of transparent overlay applied as in the screen shot.If I open the same file on my laptop with Photoshop 6 I see the alpha and no 'transparent' overlay so I know the file is ok. Am I missing something blindingly obvious with PS 7 that I've as yet failed to spot?Any pointers greatly appreciated.-Deanhttp://www.dmcity.com/uploads/ps7.jpg