Library does not rebuild

Hi,
I am new to Arduino but came from a programming background. In getting acquainted with the programming environment, I jumped right into the creation of libraries. I could not get my library to rebuild after I made changes to the .CPP or the .H files.
I then created a sketch with the "morse code library example" and got it build and working on the board. Then I made changes in the Morse library and again, it would not implement my changes (even though, when the compiler is in "verbose mode", it shows that morse.cpp is being compiled). I then deliberately put a syntax error into the morse.CPP file and it was never detected during the compilation.

HELP! What can be going on? What am I missing?

Thanks!

You sure you don't have multiple copies of the library on there somehow? Maybe you're modifying one copy but the other is the one actually being used.

I thought of that, so I searched the whole disk ( just in case my late-night programming cause unintended consequences) but only found one copy!

Where have you put it? Maybe read this:

If I am ever in doubt I just put this line into my library:

#error foo

Make sure you save the library changes (I know, it's obvious) because the IDE won't do that or warn you to do that.

Thank you Nick,

Your reference was very helpful. I had moved my sketches under a separate directory on my D: drive and somehow I missed the fact that for the libraries, it was still looking into directory branch under C:\users....

Thanks for your help!