Internal Server Error

Hi and thank you for such a great plugin! I have successfully migrated a number of sites already.

With the site I am migrating at the moment I keep getting the same error message:

The plugin encountered an error while downloading the zip file,the following error message was returned:
Error Message : Internal Server Error

Temporary files created in **SITE-ROOT**/wp-content/wpclone-temp will be deleted.

I’ve not encountered this problem before?

How would I get around this one?

Cheers,
Jeremy