Unable to export compiled form data to .csv and .xml

To save teachers' classroom log data for one of our research projects, I put together a PDF Form using Acrobat Pro 8.1.2 for the Mac. Everything seemed to work fine. I created the unique, sequential fields for the form and tested it. Now we are trying to work with returned data and it's not going well.

I can compile the returned forms. And they display in Acrobat (though the form field titles are really impossible to read with the single-line column headers of the dataset pdf. To work with the data, we need to export it. And here's where it breaks down.

Acrobat is exporting an incomplete .csv file. When I open it in Excel, I get a "File not loaded completely" error message. If I open it in text edit or in SPSS (a statistical program), I don't get the error message, but I don't get the complete data, either. Any ideas what I'm doing wrong or what I can do to fix it? I have compiled about 13 returned forms with probably 500 or so fields each. I've tried both the export data button as well as the merge data command. Same result. I lose about 10 fields from the front of the documents (right after file name) and more than 10 from the back of the documents. Any help is greatly appreciated. I'm rather desperate. Yes, I've got only 13 forms in, but hundreds on the way. Yikes.