Yesterday based on this article I was able to fix the security issues that arise from opening file dialog windows in Flash Player 10+, now you can import/export saves directly to the disk using that familiar Windows method. If you have an old save string, you can simply paste it into a file and import that, just make sure that there's no extra characters or blank lines in the file, just the string itself.
Furthermore you can now load saves created with any earlier version of the game (in theory), I haven't tested this fully, but any problems should be trivial to fix, please let me know if you encounter any.
My next goal is to get the game working on mobile platforms, I should have some results in a day or two.
As always, thanks for support, you can see these changes now in the dev release.