It seems that you are having some issues in order to get the remote connection to your Slingbox PRO HD, although the Slingbox works fine at home.
If you get the "cannot find the Slingbox" error message, the isue is related to the security software. Even though we can not tell you which adjustments to make on your security software (for obvious security reasons), we encourage you to check this link and follow the indications.
The information included in this link will encourage you to contact your security software provider in order to know what adjustments to make.
On the other hand, if you get the "Internet Viewing Set Up Complete: Yes" message, it means that the Internet Viewing feature has been enabled in your Slingbox and now you will be able to get the remote connection.