"kernel-image-2.6" is a virtual package provided by:
  kernel-image-2.6.8-3-k7-smp kernel-image-2.6.8-3-k7
  kernel-image-2.6.8-3-686-smp kernel-image-2.6.8-3-686
  kernel-image-2.6.8-3-386 kernel-image-2.6.8-2-k7-smp
  kernel-image-2.6.8-2-k7 kernel-image-2.6.8-12-em64t-p4-smp
  kernel-image-2.6.8-12-em64t-p4 kernel-image-2.6.8-12-amd64-k8-smp
  kernel-image-2.6.8-12-amd64-k8 kernel-image-2.6.8-12-amd64-generic
  kernel-image-2.6.8-11-em64t-p4-smp kernel-image-2.6.8-11-em64t-p4
  kernel-image-2.6.8-11-amd64-k8-smp kernel-image-2.6.8-11-amd64-k8
  kernel-image-2.6.8-11-amd64-generic kernel-image-2.6.8-2-686-smp
  kernel-image-2.6.8-2-686 kernel-image-2.6.8-2-386
You must choose one to install.