Richard Formidoni, Technology Product Manager of Korg USA posted an update on Korg Forums regarding the double triggering issue:
Thanks for your patience. Again, I’m posting this on behalf of Korg Inc.:
We have been hard at work investigating the small percentage of Kronos 73 and 88 users who are experiencing a double-triggering issue. We are pleased to announce that we have successfully tested a solution, and we will be including this adjustment in future Kronos production. We will continue our analysis, but we would like to make this solution available to users who are affected. Please contact your local Korg distributor if you are experiencing this behavior, and please also note that there is no benefit for this solution being applied if your Kronos 73 or 88 is not one of the small percentage that is exhibiting this issue.
Update: the fix is a hardware and a software fix. Probably they will replace the keybed and the software will be updated to 1.5.2 (from 1.5.0). The reactions of users who have their Kronos repaired are very positive.