Port Explorer wont start up, gives error message

Unfortunately, my port explorer wont start up and instead gives me this message.

"Integrity check failed. This File has been modified.
Reason might be a possible Virus Infection!

Ï have ran anti-virus software on it twice to no avail and I have also deleted it and reinstalled it 3 times to no avail. Please tell me someone has seen this before and can help me out. This message is in a small box with a yellow triangle to the left of the message and inside the triangle is an exclamation mark and in the title bar it says Portexplorer.exe

Any guidance would be appreciated. And yes the virus signatures were up to date on the Anti-virus software.

 

Hi Jim, Was your anti-virus running resident when you tried installing PE?

 

Jim,
Where did you download Port Explorer from? If you downloaded it from our site (http://www.diamondcs.com.au/portexplorer/) there shouldn't be any problems - we've never had any similar reports before. Can you please submit your portexplorer.exe file to us? (http://www.diamondcs.com.au/index.php?page=contact)
Thanks