well, I faced this issue before. I fixed it by converting the types of encoding.
first: does your text comes from Data Base? or its inside your page like HTML tags?
if your text comes from Database please use this:
System.IO.MemoryStream stream = new System.IO.MemoryStream();
System.IO.StreamWriter writer = new System.IO.StreamWriter(stream, System.Text.Encoding.GetEncoding("WIndows-1252"));
writer.Write("**#your text from database#**");
writer.Flush();
stream.Position = 0;
System.IO.StreamReader xx = new System.IO.StreamReader(stream, System.Text.Encoding.UTF8);
string converted = xx.ReadToEnd();
and if your text inside your page:
just do save as and select UTF-8 encoding
thanks