why anyone wants gemeni is beyond me, but down to personal preferance i suppose.
have you not tried digitalkaos image available from our downloads here Digital Kaos - Downloads - Digital Kaos v1 Image for DM500 (cable and sat) you will get lots of support for it here as it's been made specially for here.
also have you tried nabilosat 0.8maxvar? dream of pirates? PB enigma?
but if you still want gemeni 4.20 is available from here Digital Kaos - Downloads - Gemini 4.20 Image for DM500
hope this helps m8