For Dead Space 3 DUPLEX release, i've tested the 3.55 Fix by propJOE (BLUS31053_DEADSPACE3_PATCH101FXD-propJOE.pkg), who claims that the save issue has been fixed.
Although the in-game saves now work if you go back to the game's menu and load your progress, but when the game is exited completely and started again from the XMB, the save isn't recognised, in fact, the save isn't shown at all, and you'll start again from scratch.
So, basically, you have to leave DS3 running on your PS3 until you finish the game. It's not practical and i don't want to overheat/kill my PS3 to leave it running DS3 for several days.
Someone REALLY needs to release a PROPER FIX for the save game issue!! It's been so many days since DUPLEX released this game and Dead Space 3 is such an awesome sequel in this fantastic franchise! It doesn't make much sense at all... Why the scene groups (and all the independent smart coders) don't seem concerned to fix this wildly popular release??