Wire Library broken in Arduino-15 about arduino HOT 4 CLOSED

Deleted Wire.o and twi.o so they would recompile. That fixed the problem.

So the source code for the libraries seems to be okay?  Has the problem 
reappeared since?

The problem has not reappeared. I looked over the Wire library and didn't see 
any
changes since the last version. I am curious however if the Wire library will 
work
with the Arduino Mega since I did not see any changes in the library to 
accommodate
that uC. I guess it assumes that it's basically the same as the Wiring board in 
terms
of I2C functionality.