I'm working on this same thing today, and we are getting it to work.
First make sure that you define a data range for your Excel spreadsheet
information. Next, follow the instructions at:
http://www.ehow.com/how_12175930_connect-adobe-livecycle-excel-worksheets.html
After building the connection string in Step 3, be sure to select the
Table radio option and select your data range from the dropdown list.
Hope this help!