Unable to upload digital products using WP e-commerce plugin

Hi

I have been using WP-ecommerce plugin for more than a year for my website https://www.maximus.my

Recently i can’t upload any pdf files (even less than 10MB) on my product [pages] https://maximus.my/learning/ict-ebooks/website-authoring/ . The file uploads as 0.00MB. I have contacted my web-hosting company and they have advised me to seek support from WP support.

I feel this problem has occured after i recently updated your WP e-commerce plugin. Could you please advise me or provide me technical support to resolve this issue?

I will appreciate your kind support.

zee