HELP! apt-get

hyu163

[root@localhost ~]# apt-get install synaptic

Reading Package Lists... Done
Building Dependency Tree... Done
You might want to run `apt-get -f install' to correct these:
The following packages have unmet dependencies:
  gtk+-devel: Depends: XFree86-devel
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

[root@localhost ~]# apt-get -f install synaptic

Reading Package Lists... Done
Building Dependency Tree... Done
You might want to run `apt-get -f install' to correct these:
The following packages have unmet dependencies:
  gtk+-devel: Depends: XFree86-devel
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).


Why????? What to do????? Thanks