Port 25 Not Stealth

Ever since I have have Norton IS 2011 installed, Symantec Security Check always shows port 25 closed but not stealth. I have run Symantec Security Center multiple times and port 25 is always closed but not stealth. It’s the only port that shows as not stealth. However, when I run other online port scan tests from sites such as Gibson’s, etc. port 25 always shows as stealth. Does Symantec’s online scanner have a problem with it’s own software?