KR has been getting a lot of flack lately over at Kongregate for lost saved games so I decided to look into options for solving this issue.
Traditionally devs rely on some cookie scheme to store saved games(SharedObjects for flash), sadly this scheme is prone to problems since the browser and other apps routinely delete cookies and other saved state. One work around is to have the game portal host saved games but not all hosts offer this service.
How about a true local save solution instead? As of version 10 and up flash allows users to load and save files locally to their machines by using the FileReference API. No more sandbox security issues to worry about; you only have to ensure that loads and saves are user-initiated via mouse clicks. I have done it myself and its fairly easily to take an object instance representing save state and write it to a ByteArray and then have FileReference::save() save it to the user's location of choice.
Of course the downside of this method is that the user has to manually initiate the save(i.e. press a button) but this method might help to alleviate some the gripes some players have with saving.