Bug with the Google API daterange modifier?

I'm getting very bizarre results when I use the daterange modifier with queries in the API... I've found some queries that give results in the 100's but should give much higher results. For example:

the query:
Google daterange:2453481-2453486

yields 313 results

while the query:
Google good daterange:2453481-2453486

yields 2360000 results

How is this possible? Similar results occur if you substitute Microsoft for Google but not Yahoo for Google. Removing the daterange modifier yields more predictable results. What on earth is going on??

It is my understanding that the query terms are dependent on the other terms, meaning a query "A" should always yield more results than a query "A B" becuase the latter query returns only results that contain B from a subset of results that contain A. How on earth is it possible for a query "A" to return less results than "A B"?? Is there a bug in the daterange or is there some undocumented query format required for the daterange modifier? I've found that most query strings with the daterange yield predictable results but the Google and Microsoft results are very important to me and I've found a few other random combinations that yeild similar strange results. I'm completely confounded and would like to be able to use the daterange but as is I'm thinking that there is something wrong with it.

Any ideas anyone? Anyone else ever experimented with this? Am I the only one getting these results??? If you do the query manually in the Google web page then you get completely normal results. This problem only seems to be found in the API results.

Thanks for any help!
Justin Chase