I have experienced interesting behavior while using programmers notepad (v.2.0.6.1) and smarty (v.2.6.17).
When I use UTF-8 encoding on a *.tpl file, and smarty parses the *.tpl file three hex values are places at the beginning of every *.tpl file that is included in the php. They are: BE BB BF I believe. This is only a problem because ie7 interprets these in the same way that it interprets a comment before the doctype statement. When you put a comment before the doctype statement in ie you are put into quirks mode. And this in turn breaks my css. I have solved the problem by coding the files in 8-bit format instead of UTF-8.
I have not tried using a different editor and encoding in UTF-8 and running it through smarty.
I have however, tried to make *.php files with programmers notepad and these hex characters were not added to the beginning of the files.
I may have some setting turned wrong in smarty and/or programmers notepad but i don't know i just thought that someone else might like to know if it were a bug in either program
-michael