1script - 10:15 pm on Jan 26, 2012 (gmt 0)
Sounds like a redundant test - it's almost a guarantee that an internal page would be #1 better targeted and #2 better from usability stand point (one-page sites being a special case).
often replacing the exact position of the homepage listing with the internal page - almost as if some type of internal usability test is being done to select the better of the two pages.
I only get alarmed when the homepage does not return as serp #1 for the domain name - the only query where it should reasonably prevail because that's the most often used anchor in links to it. Any other query - there may be so many reasons why it's not #1 that it's probably not worth your time to investigate.