Bought the Steam version of Double Agent while it was on sale last week, and ive noticed the game isnt using the latest version on Steam, v1.02. This is obviously causing problems, like not being able to use the unlocks in single player or even get online with multiplayer. Could a mod or whoever look into this ?

Try disabling the UAC and firewall to get the update. Heard it might work.

Yeah ive tried the patch manually, but sadly, while SP works, MP starts asking for the DVD to be in the drive .

Did you try the 1.02 patch or the 1.02a patch?

The 1.02a patch removes the DVD check.

Find it @ http://patches.ubi.com

The only time when update for Double Agent by STEAM worked for me was, when I went to Multiplayer and pressed "Online".
I got message that my game is not up to date, so I picked "Yes" and then game closed and update started