Bush runs two companies into the ground - what's this all about?

Upon reading magazine clippings for Fahrenheit 9-11 (a film that I haven’t yet seen) I read some cursory details about how ‘Dubya’ ran two companies into the ground due to mismanagement.

Of course the film itself contains much more information than just this, but I’ve heard this being said many many times before and since.

Exactly what are the details of this and how true are the allegations of mismanagement? How realistic is it to say that decisions he made were responsible for the companies demise?
–I’m not a US citizen so I don’t really know what all of this pertains to. Need some background info and help in understanding. –

It’s tough to find information about Bush’s business experience that doesn’t drift off into thinly-veiled accusations of fraud, ties to the bin Laden family, and so on. However, this account, from the Washington Post, seems to be pretty straightforward. Just to hit some of the summary information:

The long and the short of it is that Arbusto, his first company, was essentially bankrupt when Spectrum 7 bought it, Spectrum 7 was losing money when Harken bought it, and Harken was in trouble when Bush bailed out of that one (at each buyout, Bush took on a management role in the purchasing company, until he left the Harken board of directors in 1990). His sale of Harken stock in 1990 drew the attention of the Securities and Exchange Commission (Bush had failed to meet some reporting requirements, and there were allegations of insider trading), but the SEC decided that no enforcement action was warranted.

The article itself is quite long, with considerable detail, so you might be able to draw your own conclusions regarding whether Bush’s business failures were the result of incompetence or just bad luck. There’s probably no factual answer to that question.