Data import

I need to import 54000 records to a DB I've set up in Zoho Creator. I've tried .xls, .tsv, .csv formats. None of these work properly when importing records containing national Danish characters. You just get the "lozenge" thingy w the ? inside of it.
I've then tried to import data in chunks via the past-process. Doing this I can be lucky to get some chunks of data into the base, but the next time I do it the import process fails w an error message stating Zoho will get back to me on this. I haven't had a smidgen of reaction from Zoho. If this is what Zoho is about I surely cannot base my business on their solutions and will have to offer my clients other solutions.

Best, Joern Wennerstroem