The reason I left...
Reminds me of the reason I left one place. Luckily the IT Director realised what was going on and arranged a month's "garden leave" for me when I handed in my notice.
Long story, the IT Manager, who I'll simply call "Dick" (pretty much everyone in the company called him that), was of the arrogant "I know more than anyone else and I can't do anything wrong" type.
So apparently he owned a multi-million dollar oil exploration data company in the USA, had a Cray supercomputer in his barn, used to be on the Olympic archery team, completed 6 degrees at University at the same time over just 18 months, counted Richard Branson as a personal friend, could play classical piano to professional level, you get the picture. Lived in a 2 up, 2 down in a cul-de-sac in Gloucestershire.
Somehow this genius managed to program part of the code to the billing system, a third party system no less, that resulted in random debits and credits being added to customer's accounts if only a partial payment was made. By random I mean anything from a few pence to thousands of pounds. Part of my job was looking into why it was doing this, and when I finally found the cause we got it fixed. Cue testing of the reports that go out to the client, which "Dick" promptly tells me are absolutely fine because he's written them. And which promptly showed the thousands of pounds of un-billed customers that owed money because of the bug he'd introduced in the first place.
As the person running the report (on his orders) I'm promptly called in and put on notice (it's at this point the IT Director calls me in and says he can at least guarantee me a month's wages, which on the grounds that saving my job means working with the manager from hell straight after dobbing him in suddenly sounds like a great idea). Day of the meeting I promptly hand over my resignation and proceed to discuss in great detail how much of a complete idiot my boss actually is (including how for the last 3 years he'd been calculating VAT wrongly on all the client reports, despite being told he was doing it wrong. He'd been calculating VAT as 17.5% of the Sale price). Needless to say I enjoyed that. Almost as much as I enjoyed the month's holiday on full pay after the IT Director informed HR that they had to pay me for that month as technically I was still employed despite being on garden leave.
As far as I can tell the company folded about 2 years later. Probably as a result of losing clients due to the IT Manager's incompetence.