This is how I resolved my issues (Savegame not detected).
The problem seems related to the quest " The Ashes of Vizima" that stuck in a previous state also if it's completed, making the savegame not detected, i presume cause the Witcher 2 check if that quest is completed to determine if it's importable or not.
So, download The Witcher Editor, backup the save you want import, open it in TWEditor and check in the "Quest" label, if you have saved for example in the Ice Plains or after killing the Grand Master the quest "The Ashes of VIzima" should be completed ('cause you complete it entering in the cloister), if it's in the "started" quest, your savegame would not be detected.
At this point you could try two different things:
a) Load a previous savegame, for example at the beginning of the Epilogue or just before the Zeugl fight and complete the game again, hoping that quest don't bugs itself again.
b) You have to make some tricky work with the Witcher Editor
-b1) Download a savegame that's being detected.
-b2) Open it in TWEditor, "unpack" it in a directory
-b3) Make a backup of YOUR savegame (if you have not done yet)
-b4) Open it in TWEditor and "unpack" it in a directory (DON'T Close TWEditor YET!)
-b5) Copy the file "q6001_wyzim.qst" from the the unpacked WORKING savegame
-b6) Paste and overwrite the one in YOUR savegame UNPACKED directory ( b4)
-b7) "Repack" your savegame (using TWEditor) and Save.
-b8) Load YOUR savegame in The Witcher, check if it's working then SAVE IT
-b9) Exit the game, Launch TW2 and your savegame should be detected.
Hope it helps!
YOWZA! Major props to Yakkuz for posting the solution to this one! I followed your instructions and it worked perfectly! Maybe CDP will issue a patch that will make this a lot easier... or perhaps patch TW2 to just overlook the state of the Ashes quest. Thanks!