NIS 2010 Blanks Out Content of Emails

I bought the opt-out trial of NIS 2010 because my favored Kaspersky Internet Security 2010 was blanking out the content of emails from some domains in my "allowed list." In other words, the emails would arrive with no content. But if I forwarded them to myself, they would arrive in code -- jibberish to me.

 

So I'm trying NIS 2010 -- and surprise of surprises, emails from another domain are arriving blank and if I forward them to myself they arrive in find shape. The emails that had been arriving blank when using Kaspersky 2010 arrive just fine with NIS 2010 installed.

 

So I'm writing to see if anybody might have a clue as to what could be causing this behavior? I'm at a loss to figure it out. The folks at Kaspersky tech support (which is normally superb and in the USA) couldn't figure it out either. I'd like to be able to stick with NIS 2010 because it does not slow down my computer (which is a pretty high speed unit) like KIS 2010 does and NIS 2010 seems to do a better job of protecting (the downsides I've found with NIS 2010 is that it does not integrate with Thunderbird, it does not accept wildcards for the email addresses in the allowed and blocked lists and doesn't let you import into those lists unless you import from Microsoft products; nor does it make it easy to disable protection and disconnect from the Internet when you have to install an application -- all things that KIS 2010 does superbly).

 

So if the collective souls here can help solve this issue, you can save a sale for Norton. Thanks much.

 

Email application: Mozilla Thunderbird 2.0.0.23

OS: Windows XP Pro, fully updated