I had an employer that reneged on my expat agreement. It wasn't like they were paying for the expensive $25K per year per kid schools, they were paying a total of $5K per year per kid (for a total of $20K). So, out of the blue, he says that this isn't in my 'contract' (a piece of paper drawn up only to get me a work permit) so he is cancelling it and going to exact it from my salary.

Then, a couple months later, he gets my expense report for my cell phone, it's the same as it's been for 5 years, about $300 a month (from all the roaming while I travel around China and Asia). He decides that he is also going to exact everything above $100 from salary after the fact, back to when I started working for the company.

And then in June, when I submitted my resignation, he was shocked that I gave only 30 days notice. But I DID give notice. Luckily, I handed it in literally the day after my vesting date. Which he said was intentional, and which later, I learned that it was indeed that he wanted to force me to quit prior to that date so that the company could save all the vested funds that they had put into my 401K.

So, I hear you, and if that's the situation you are in, then the modification I'd make is to ask my new employer to move my start date back a month so that you can give adequate notice and handover. The new employer will think you are a great employee. The old employer will still be a little grumpy, but you'll be vested and have a clear conscience.