VMWare install can't find header files

[Andrew Malcolmson <andzy@imap-mail.com>]

I'm installing VMWare player and have got to the stage where the
installer wants to build a module.  The prompt shows the following:

> What is the location of the directory of C header files that match 
> your running kernel? [/usr/src/linux/include] 

Following other posts I've installed the header package for my kernel
(2.6.18-4-xen-686) and created a link for so that /usr/src/linux points
to /usr/src/linux-headers-2.6.18-4-xen-686/

However, the installer responds with this:

> The path "/usr/src/linux/include" is a kernel header file directory, 
> but it is not part of kernel source tree.

Ideas are welcome