Apt-Get kernel doesn't match running kernel

I made the mistake of doing an upgrade on my box today using the Synaptic Package Manager and now everything is dorked up.

Specifically I'm running the 2.6.15-21-686, but when I go into Synaptic gui to install the kernel source and kernel headers all I see is the 2.4 kernel. ???????????????

Same thing when I do it from the command line:

jackal@jackal:~$ uname -a
Linux jackal 2.6.15-21-686 #1 SMP PREEMPT Fri Apr 21 16:57:03 UTC 2006 i686 GNU/Linux


jackal@jackal:~$ apt-cache search kernel | grep ^kernel-headers
kernel-headers-2.4.27-2 - Header files related to Linux kernel version 2.4.27
kernel-headers-2.4.27-2-386 - Linux 2.4.27 kernel headers for 386
<..snip..>
kernel-headers-2.4.27-2-686-smp - Linux 2.4.27 kernel headers for PPro/Celeron/PII/PIII/P4 SMP
<..snip..>
kernel-headers-2.4.27-2-k7-smp - Linux 2.4.27 kernel headers for AMD K7 SMP

How do I fix this? I need the kernel headers for the 2.6.15-21 kernel since that's the kernel I'm running.