moving a file with template code to another directory breaks compile

[u19809]

The compile lines below only have two differences : the location and the
name of the WxAction.cpp / WxAction_A.cpp file.

The files are identical ( checked with diff).

WxAction contains definition code of a template which is defined in
WxAction.h (in both cases).

WxAction.h resides in the same directory as WxAction.cpp (but not
WxAction_A.cpp)

When I compile with the first compile statement I get :

$ nm i686_LinuxGnu_.arch/debugthreaded_gcc3-b/WxAction.o | grep Empty
         U wxEmptyString
         U _ZN18AC_ActionVariant_t5EmptyEv
000001ec T _ZN18AC_ActionVariant_t7DoEmptyEv
00000000 W _ZN18wxBaseArrayPtrVoid5EmptyEv
00000000 W _ZNK12wxStringData7IsEmptyEv
00000000 W _ZNK8wxString7IsEmptyEv

With the second compile I get ...

$ nm i686_LinuxGnu_.arch/debugthreaded_gcc3-b/WxAction.o | grep Empty
         U wxEmptyString
00000000 W _ZN18AC_ActionVariant_t5EmptyEv
000001ec T _ZN18AC_ActionVariant_t7DoEmptyEv
00000000 W _ZN18wxBaseArrayPtrVoid5EmptyEv
00000000 W _ZNK12wxStringData7IsEmptyEv
00000000 W _ZNK18AC_ActionVariant_t7IsEmptyEv
00000000 W _ZNK18wxBaseArrayPtrVoid7IsEmptyEv
00000000 W _ZNK8wxString7IsEmptyEv


WHY ALL OF A SUDDEN TEMPLATE METHOD 'Empty' IS UNDEFINED ????

g++-3.4 -c  -pthread -Wall -Wpointer-arith -Wcast-align
-march=i686 -fPIC -rdynamic -g -DAP_D -DAP_T -DARCH=i686_LinuxGnu_
-DARCH_HW=i686 -DARCH_OS=LinuxGnu -DARCH_OSV= -DARCH_Sub= -D__i386__
-D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -D_LARGEFILE_SOURCE=1 -DAC_THREADED
-D_REENTRANT -D__WXGTK__ -DNO_GCC_PRAGMA -DWXUSINGDLL -DGTK_NO_CHECK_CASTS
-DXTHREADS -D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -D_LARGEFILE_SOURCE=1
-I/usr/include/wx-2.6 -I/usr/lib/wx/include/gtk2-unicode-release-2.6
-I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -I/usr/include/atk-1.0
-I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include -I/usr/X11R6/include -I.
-I/media/External/projects/AP/MSP/Client/i686_LinuxGnu_.arch/debugthreaded_gcc3/
-I/home/u19809/projects/AP/APEE_RT/gcc3/
-I/media/External/projects/AP/MSP/Client/i686_LinuxGnu_.arch/debugthreaded_gcc3/behaviors/wx.cat
-I/home/u19809/projects/AP/APEE_RT/gcc3/behaviors/wx.cat
-I/media/External/projects/AP/MSP/Client/i686_LinuxGnu_.arch/debugthreaded_gcc3/include/wx.cat
-I/home/u19809/projects/AP/APEE_RT/gcc3/include/wx.cat
-I/media/External/projects/AP/MSP/Client/i686_LinuxGnu_.arch/debugthreaded_gcc3/include
-I/home/u19809/projects/AP/APEE_RT/gcc3/include
-I/media/External/projects/AP/MSP/Client/i686_LinuxGnu_.arch/debugthreaded_gcc3/behaviors
-I/home/u19809/projects/AP/APEE_RT/gcc3/behaviors -o
i686_LinuxGnu_.arch/debugthreaded_gcc3-b/WxAction.o
i686_LinuxGnu_.arch/debugthreaded_gcc3/WxAction_A.cpp

g++-3.4 -c  -pthread -Wall -Wpointer-arith -Wcast-align -march=i686 -fPIC
-rdynamic -g -DAP_D -DAP_T -DARCH=i686_LinuxGnu_ -DARCH_HW=i686
-DARCH_OS=LinuxGnu -DARCH_OSV= -DARCH_Sub= -D__i386__
-D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -D_LARGEFILE_SOURCE=1 -DAC_THREADED
-D_REENTRANT -D__WXGTK__ -DNO_GCC_PRAGMA -DWXUSINGDLL -DGTK_NO_CHECK_CASTS
-DXTHREADS -D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -D_LARGEFILE_SOURCE=1
-I/usr/include/wx-2.6 -I/usr/lib/wx/include/gtk2-unicode-release-2.6
-I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -I/usr/include/atk-1.0
-I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include -I/usr/X11R6/include -I.
-I/media/External/projects/AP/MSP/Client/i686_LinuxGnu_.arch/debugthreaded_gcc3/
-I/home/u19809/projects/AP/APEE_RT/gcc3/
-I/media/External/projects/AP/MSP/Client/i686_LinuxGnu_.arch/debugthreaded_gcc3/behaviors/wx.cat
-I/home/u19809/projects/AP/APEE_RT/gcc3/behaviors/wx.cat
-I/media/External/projects/AP/MSP/Client/i686_LinuxGnu_.arch/debugthreaded_gcc3/include/wx.cat
-I/home/u19809/projects/AP/APEE_RT/gcc3/include/wx.cat
-I/media/External/projects/AP/MSP/Client/i686_LinuxGnu_.arch/debugthreaded_gcc3/include
-I/home/u19809/projects/AP/APEE_RT/gcc3/include
-I/media/External/projects/AP/MSP/Client/i686_LinuxGnu_.arch/debugthreaded_gcc3/behaviors
-I/home/u19809/projects/AP/APEE_RT/gcc3/behaviors -o
i686_LinuxGnu_.arch/debugthreaded_gcc3-b/WxAction.o WxAction.cpp