Mikomi dc-7120 webcam on Skype

installed a mikomi dc-7120 webcam on my toshiba laptop, running windows xp.
The video picture soon appeared, and after a bit of trawling through the options, i eventually got the sound to work also.
but when i connect to Skype, and can see/hear my contact at the other end [and also see my own webcam image in a separate window], skype does not seem to accept any sound or image from my webcam. All i see [and all my contact sees] is a black square.
although the skype video settings shows a webcam type as 1.3mp camera [but the mikomi is 5mp] there seems to be no way to test or manually introduce my webcam into skype.Any ideas?