Hi troubled - you have my every sympathy, as I read your post it sounded very familiar. I had a management job with a new company I gave it my all, negotiated many favourable discounts new buiness etc, unfortunately the comapny was handed to son to run who was useless, the company started losing money hand over fist. I took a rep to lunch after negotiating a deal that saved several thousand ponds and charged it to the company account as I had done many times before - lunch was 2 sandwiches at total cost of �5 - I was sacked for unauthorised spending. I was devastated but I was paid money owing me. Several other managers were sacked over similar minor 'offences' One week later the liquidators were called in and the rest of the staff lost their jobs. My sacking was a ploy to avoid redundancy payments!!!
My advice re jobhunting. Why not tell the truth but also tell them 'you absolutely did not do what you are accused of' tell them that to prove it you will do the job at 25% less than salary offered, when you are cleared they can take you on at full salary if not then they can get rid of you. They have nothing to lose, all your skill and experience at less than the market rate until you are cleared and they're not stuck with you if you're not. Don't go for big astablished companies go for one's that are smaller and more personal where you get to deal with the owner rather than just an employed manager.
You'd be surprised - I've taken a chance on people who I just have a good feeling about....and I've never been let down yet.