We have several users having issues downloading reports out of CRM (irregardless of export format) ... they all get the same Windows Internet Explorer error box that reads:
Internet Explorer cannot download ...sis&Format=mht&Extension=.xls from secure-ausomxXXX.crmondemand.com
Internet Explorer was not able to open this Internet site. The requested site is either unavailable or cannot be found. Please try again later.
I've instructed them to: Go Tools - Internet Options - Advanced and tick Use HTTP 1.1 through proxy connections
But that doesn't always work...
Originally I thought it had to do with the version of IE however, I'm noticing the error coming from both IE7 & IE8 now.