We had this problem too for some time, that combat just went on and on. Until we changed the critical, special, failure and fumble rules that is. Now we have criticals at 1/10th skill rounded down, specials at 1/2 skill rounded down, all rolls above 90 is a failure (if not a fumble) and fumbles at 90+1/10th skill rounded down. It REALLY speeds up the combat. The players were horrified when I introduced the rule, fearing the swift death of their characters, but have gotten used to it now. (As a side effect it also provides better granulation for opposed non-combat skills).