app crashes during csv import

I tried importing a csv file rather than pasting (to create a db).
The fields showed up with 'number" as default not "text" as expected.
It also created an empty field where there was none in the original spreadsheet.
During the field change the browser (firefox) froze.

Replicating everything in IE7 created the same scenario except the import process/IE crashed. Going back into creator the imported file fields had disappeared.