SteveWh - 11:13 am on Apr 13, 2011 (gmt 0)
If the file has only regular 7-bit ASCII characters in it (which is common), it is also legal UTF-8. An editor might have saved the file with the BOM at the top.
Notepad++ is another editor (for Windows) that can save the file without the BOM.
In one editor (unfortunately don't recall which), I discovered I could remove the BOM by putting the cursor at the very top of the file and hitting Backspace. Nothing visibly happened, but it got rid of the BOM.
A "hexdump" utility can show you the actual bytes in the file. It's "hexdump" or "hd" in Linux. Somewhere, there should be an equivalent utility available for Windows.