gnumake 3.79.1 bug?

[Randy Yates]

It appears that there is a bug in gnumake that arises when
a variable is redefined. For example, if I define "EXE = .a"
in my main makefile, then specify a build rule for a target
"myproject$(EXE)", then include a second makefile that redefines
"EXE = .out" and makes some other build rules for other targets, 
then the first build rule seems to get confused. If I put "echo $(EXE)"
I see the right value (".a"), but the target acts as if the second
value (".exe") is present and the file does not recognize the command
line target "myproject.a". 

Is this a bug? Is this a known bug?
-- 
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
randy.yates@sonyericsson.com, 919-472-1124