Sometimes getting "API requires authorization" from intuit anywhere api after a fresh oAuth handshake
I received this error as well and am posting this as pointer for other who stumble upon this. Error Code 22 (Authentication required) for me meant that the OAuth signature was wrong. This was confusing because I couldn't find this error listed in the Quickbooks documents for reconnect.
I was signing the request as a "POST" request instead of a "GET" request which is what Quickbooks requires for calls to the reconnect endpoint.
After completing the oAuth handshake with Intuit Anywhere (AI), I use the API to get the HTML for the blue dot menu. Sometimes, the expected HTML is returned. Other times, I get this message 

This API requires Authorization. 22 2013-01-10T15:32:33.43741Z

Typically, this message is returned when the oAuth token is expired. However, on the occasions when I get it, I can click around in my website for a bit or do a refresh, and the expected HTML is returned. I checked the headers being sent and, in both cases (i.e., when the expected HTML is returned, and an error is returned), the request is exactly the same. I wouldn't be surprised if this was a bug in Intuit's API, but I'm trying to rule out any other possibilities first. Please let me know if you have any thoughts on how to fix this. Thanks.
Update: It seems the problem is occurring only when I do a refresh. This seems to be the case both in Firefox and Safari on OSX. It sounds to be like a Javascript caching issue.