I find there will be some problems if you edit Smarty tpl files with dreamweaver. Dreamweaver will automatically make some changes, so I try to find some solutions about this.
I found an article from http://smarty.incutio.com/?page=SmartyDreamweaver, however it doesnot work in my computer, I got the result like this:

So I continue search, at smarty.php.net I found a good plugin that works:

You can download it at:
http://smarty.php.net/contribs/misc/dreamweaver_smartytags.zip
Smarty Tags for DreamWeaver
Just copy the files into DreamWeaver's "Configuration\ThirdPartyTags"
directory and enjoy the visually stunning ;) Smarty tags within DW.
Author:
Andrew Izsof
flatline@hardwired.hu
Hope this is useful for you!