Hi Rgenis,
I would make sure that Trend had all email scanning options turned off. If that does not help, then try a test and uninstall Trend. If it works fine without Trend installed, you could use something like the free Avast instead. I have no problems with Windows Live Mail using it.
http://www.avast.com/eng/avast-4-home_pro-revision-history.html
Hope this helps you,
Shawn