My 2010 filing was audited in 2013. Went round and round over the 529 details, receipts, etc. After 4 additional filings of the same information, (and a few hundred more dollars for the accountant) I provided to begin with, they sent me a $49 check with no explanation.
We went through an audit for the same 2010 tax year, but in 2012.
It was a taxpayer compliance audit: the "super-audit" that checks every little detail. The IRS never indicated any problem: the examiner's only question was why we didn't claim a small tax credit (answer: my accountant would have spent more time and money collecting the information required).
At the outset, the examiner admitted that this was a waste of his time. The audit ended with no changes, except for another bill from my accountant.