What TV system are you using and shooting video on? Are you in a country that uses NTSC or PAL?
When you installed the program did you ensure that you set it for your country?
When you look under the Edit menu, on Project Settings/General, what settings does it show?
I'm in the UK and it is only DVDs burned from Premiere Elements that shows this message. I have just checked in General tab as you suggest, but see no option for PAL.
Did I check for correct country on installation? I can't remember. Is there any way of checking?
I'm not sure, based on what you've told me, if you've installed your program to default to PAL settings.