Can't Import Anything

I have tried importing data from an excel sheet a number of times and have now uploaded to the test server to rule out any permissions issues.
Anyone have any thoughts?
We will not be importing ALL fields so some will be null. When we try to upload it just tells us all the records were not imported and states "error on line..." The errors are on all lines, however it's not clear what the error is.
If it's the fact we have NULL values how would we be able to import with nulls?
Test site here w/ a few simple fields.
http://demo.asprunner.net/rkjconsult_hotmail_com/testing