I have Mandrake 2006 installed & I'm trying to install
VMware 5.5 for windows.
Are you trying to install a windows version on Linux ????
If not then, you can have any no. of kernels installed but only one will be active at one time.See the running kernel from this command
Now in case you want vmware to be installed for both the kernels, you have boot in seprately into both kernels and install vmware for it.