First chance I have had to test again. Downloaded latest release and category upload worked fine but got the following warnings for product upload:
Warning: fwrite/fclose/imagesx/imagesy(): supplied argument is not a valid Image resource in…
and then it references /wp-e-commerce-product-importer-deluxe.php and /SimpleImage.php on various lines and for each image.
Hope that makes sense.
I have the latest versions of WP and E commerce. I have the store installed on only one network site.