My XRGB-2 upscaler has been a real workhorse since I bought it, but the 21-pin RGB connector started to fall apart. The plastic became brittle with age, and it'd literally crumble if you pushed it with your finger. The result was a poor connection, and it was very loose and would bend inwards when you plugged something into it.
So I replaced it. In Australia Element14 (A division of Farnell) carries the PRO SIGNAL PSG01601 (http://au.element14.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=15001&partNumber=1280720&storeId=10184) connector. It costs approximately $fuckall, and now my XRGB-2 is perfect again.
(http://nfggames.com/grafx/XRGB2-RGB21.jpg)