I seem to recall instances where the compiler would report the correct line number, but the wrong file. If you watch the compilation, you might be able to figure out which file it's in when it generates the error.
Have you modified any of the libraries?
Are you using valid settings for the serial buffers? Remember that they need to be 1 less than some power of 2. For example, 7, 15, 31, 63, 127, etc.