I always develop in Firefox, only use IE for testing. Have tried in IE7 with same results. Like I say, allows the download anyway if I click again - so it works, but probably not instilling a lot of faith in the customer (or my client!) if error messages pop up in the download process.

I suppose if it came to it I could remove the error message from wherever it's being called and print some white space, but that seems a bit dirty

EDIT

I've just realised this happens only when I try to download the file twice in succession -

e.g. if i download, then go to another page in my account say 'Orders', then go back to 'Downloads', the file is happy to be downloaded again, no error message. SO it only happens if I try to download the file twice consecutively whilst on the 'Downloads' page in 'My Account'.

Does this shed any light? Cheers!