We get this when we try downloading
File Transfer Blocked
Transfer of the file you were trying to download or upload has been blocked in accordance with company policy. Please contact your system administrator if you believe this is in error.
File name: WireframeSketcher-6.2.3.exe
Can you email me a screenshot with the error at peter at wireframesketcher.com? From the look of the error it seems to be some kind of protection policy at your company.