I had the same problem as MikeTheBike. I set up a query in MS Access and then used the Data Wizard in Excel (go to Data -> Get External Data -> From Access) to import the data from Access, and I got two blank rows. When I refreshed that table, I got one blank row. I was able to import other queries, and I double checked to make sure that running this query in Access give me a non-null result.
To fix this (and I don't know why this works, just that it did in this instance) I used "From Other Sources" instead of "From Access" in the data import, and used "From Microsoft Query". A small window pops up to allow you to pick an Access Database and then a query or a table within the database. And this worked.
Again, I'm not sure why this worked, only that it did, so if there's an Excel-Access expert out there that can shed some light on this, I'd be grateful.