Is anyone else having or had a problem with Turbolister not accepting weights?

I have tried to get back to selling (books) after a few years break. I have templates for the standard postage types I use - letter, large letter, 500g satchel and 3kg satchel and include the relevant weight with each listing. Turbolister repeatedly gives me an error message saying The package weight is not valid or is missing. I had this problem about 3 months ago when I first tried to list again, went through their help contacts system and got no help at all, deleted all my listings and templates and gave up. I have just redone my templates, uploaded one book successfully, and got the error message on the second book. Any suggestions??