Can't get correct source files for latest Dapper kernel

[Dave M G]

cilynx wrote:
> Your source is in "linux-source-2.6.15" however, to reconfig VMWare, you
> just have to point it to the headers in "linux-headers-2.6.15-20-686"
>   

If I do this, it says:
The directory of kernel headers (version 2.6.15-20-686) does not match your
running kernel (version 2.6.15-22-686).  Even if the module were to compile
successfully, it would not load into the running kernel.

Surely I need linux-headers-2.6.15-22-686? Where are they, or how do I 
get them?

--
Dave M G