AppleScript errata

Question

I'm having problems with AppleScript. First, if I restart my Mac the problems go away for awhile before they reappear. So, it seems something happens after using my Mac for awhile that triggers the problems which are then cured by a restart.
Problem 1. In the following script (user name and password changed for security) the @ symbol gets dropped when the script is run and the user name appears as xxxhotmail.com missing the @ symbol.
tell application "Safari"
  activate
          open location "https://www.hotmail.com/"
          delay 5.0
          tell application "System Events"
                    keystroke "[email protected]"
                    delay 0.25
  keystroke tab
                    delay 0.25
                    keystroke "password_xxx"
                    delay 0.25
  keystroke return
          end tell
end tell
I have a second problem with one particular web site where login fails even though the user name is correctly entered into the user name field in Safari by the AppleScript. I cannot tell if the password is being properly entered becasue it only appears as bullets ••••••• so I cannot see the text. The script is the same as that shown above except for the URL, user name and password. If I copy and paste the user name and password from the AppleScrip into the appropriate fields in Safari and press Return or Enter I get logged in just fine. It's only when running the script that login fails. Again, restarting my Mac seems to fix the problem temporarily.
This is all on my MacPro 5,1 running 10.6.8.
Any insight into what might be causing there problems or how to remedy them would be appreciated.

Answer 1

I used the locater script in this to get a new location but still doesn't answer what happened to cause it to break.
http://discussions.apple.com/thread.jspa?messageID=3621766&#3621766