I think the SSF addition to PowerMAME has been abondoned, since MAME is in the process of being changed to emulate an 'always on' state- so when you exit a game it saves its position, then when you load it again it picks up from the same point. This way, if you reset the game it will revert to the previous saved position, which would usually have been past the initial startup sequence. This also eliminates the need for hiscore.dat, since MAME behaves like the game is never powered off it never looses a games hi score.
It seems with every update they fix a couple more save state problems, so hopefully they'll have this system implemented before too long.