Here is what you need to know, Get off Rackspace Cloud sites.
Their "cloud" has a load balancer, when you issue a transaction and it takes more than 30 seconds, you're dead, they dump it and you are out of luck.
Option is to go to Rackspace managed server at $199 a month (forget it!)
I went to Hostgator Resller account for like $30 per month and ALL IS WELL!!
Trying to do a test purchase, keep getting this:
Proxy Error
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request POST /billing/cart.php.
Reason: Error reading from remote server
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Apache/2.2 Server at http://www.nitrobackup.com Port 80
Using an Add on module from WHMCSMOD.com for Livedrive.com
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Just for clarity, I am not asking if you are selling hosting services from Rackspace,
I am asking is your WHMCS website hosted ON rackspace (or mosso)?
I have been battling with Rackspace for a week trying to get the software working and they keep saying its the software and I dont believe it is.
If you host WHMCS on Rackspace or Mosso please respond and let me know your website so I can prove it runs on their system.