While trying to compile zaptel 1.2.8 on a FC5 I get the following error:
/lib/modules/2.6.19-1.2288.fc5smp/build
make -C /lib/modules/2.6.19-1.2288.fc5smp/build SUBDIRS=/usr/src/zaptel-1.2.8 modules
make[1]: Entering directory `/usr/src/kernels/2.6.19-1.2288.fc5-smp-i686'
  CC [M]  /usr/src/zaptel-1.2.8/zaptel.o
In file included from /usr/src/zaptel-1.2.8/zaptel.c:40:
/usr/src/zaptel-1.2.8/zconfig.h:9:26: error: linux/config.h: No such file or directory
make[2]: *** [/usr/src/zaptel-1.2.8/zaptel.o] Error 1
make[1]: *** [_module_/usr/src/zaptel-1.2.8] Error 2
make[1]: Leaving directory `/usr/src/kernels/2.6.19-1.2288.fc5-smp-i686'
make: *** [linux26] Error 2
[root@ngn2 zaptel-1.2.8]# 

I have the sources installed:
[root@ngn2 zaptel-1.2.8]# yum list kern*
Loading "installonlyn" plugin
Setting up repositories
core                                                                 [1/3]
core                      100% |=========================| 1.1 kB    00:00     
extras                                                               [2/3]
extras                    100% |=========================| 1.1 kB    00:00     
updates                                                              [3/3]
updates                   100% |=========================| 1.2 kB    00:00     
Reading repository metadata in from local files
primary.xml.gz            100% |=========================| 1.9 MB    00:09     
extras    : ################################################## 6294/6294
Added 3 new packages, deleted 34 old in 29.48 seconds
primary.xml.gz            100% |=========================| 392 kB    00:03     
updates   : ################################################## 1073/1073
Added 5 new packages, deleted 2 old in 4.93 seconds
Installed Packages
kernel.i686                              2.6.19-1.2288.fc5      installed       
kernel.i686                              2.6.17-1.2174_FC5      installed       
kernel-devel.i686                        2.6.19-1.2288.fc5      installed       
kernel-smp.i686                          2.6.19-1.2288.fc5      installed       
kernel-smp.i686                          2.6.17-1.2174_FC5      installed       
kernel-smp-devel.i686                    2.6.17-1.2174_FC5      installed       
kernel-smp-devel.i686                    2.6.19-1.2288.fc5      installed       
Available Packages
kernel.i586                              2.6.19-1.2288.fc5      updates         
kernel-debug.i686                        2.6.19-1.2288.fc5      updates         
kernel-debug-devel.i686                  2.6.19-1.2288.fc5      updates         
kernel-devel.i586                        2.6.19-1.2288.fc5      updates         
kernel-doc.noarch                        2.6.19-1.2288.fc5      updates         
kernel-kdump.i686                        2.6.19-1.2288.fc5      updates         
kernel-kdump-devel.i686                  2.6.19-1.2288.fc5      updates         
kernel-smp.i586                          2.6.19-1.2288.fc5      updates         
kernel-smp-debug.i686                    2.6.19-1.2288.fc5      updates         
kernel-smp-debug-devel.i686              2.6.19-1.2288.fc5      updates         
kernel-smp-devel.i586                    2.6.19-1.2288.fc5      updates         
kernel-xen.i686                          2.6.19-1.2288.fc5      updates         
kernel-xen-devel.i686                    2.6.19-1.2288.fc5      updates         
kernel-xen0.i686                         2.6.19-1.2288.fc5      updates         
kernel-xen0-devel.i686                   2.6.19-1.2288.fc5      updates         
kernel-xenU.i686                         2.6.19-1.2288.fc5      updates         
kernel-xenU-devel.i686                   2.6.19-1.2288.fc5      updates   

Any idea what the issue is ?