Try
USE Myclasslib.vcx exclusive
then
PACK

Did it work.
You said you would see to it that are not identical classlib names in the search path, OK.

But didn't you acidentally copy the class you're talking about to another classlib.
This happens very easy. You're a bit fast with the mouse in the project manager an before you know you drag and dropped (copied) the class from one classlib into another.
This still happens to me on a regular basis.

You could use the windows explorer file finder and search for occurences of your classname.
When you see the files containing your classname, you maybe can figure out, hey in this file there shouldn't be an occurence of 'myclass'.
So this can be the location where you copied your class accidentally to.

Or you could look for your WAIT WINDOW ... command the same way.
Maybe then you see it appearing in two or more locations where it shouldn't be.
Remove it from there, delete the obsolete file...

Check if the classlib isn't marked as readonly, this happens from time to time when you're using Visual Sourcesafe. When you performed a get latest version and you have somewhere (in the options or so) mark files not checked as readonly.

Last but not least.
Is your WAIT WINDOW maybe not somewhere up in the classhierarchy?

And last resort.
USE myclasslib.vcx
LOCATE FOR atc('WAIT WINDOW', Methods) > 0

Found ?

Browse
Open the memo field
Manually delete your offending line.

Close the browse
close the table (the VCX opened as a table) - USE
RECOMPILE CLASSLIB myclasslib.vcx

So now I am out of options as well.

Otherwise talk to Murphy again.

Good luck.