quickbooks update errors

We are running into issues where Quickbooks will not update gives us an the error message that something is wrong with the digital signature.

We are running the Web Proxy in transparent mode. If we disable the web proxy then the QuickBooks updates download with no problems. We also whitelisted the following sites for QuickBooks:

quickbooks.com
intuit.com

If anyone has a fix for this please post.

Thanks in advance!