[CMake] Can't unset suffix

[Wade Williams]

Using Cmake 2.4.7 on Ubuntu.

My project produces a shared library on Unix which is a plugin.   
Therefore, it does not need the standard "libxxx.so" naming.   I want  
the name to be "xsb_vatsim.xpl"

I've changed the suffix to what I want, but now I'm trying to  
eliminate the prefix and finding it impossible.

If I use:

SET_TARGET_PROPERTIES(xsb_vatsim PROPERTIES PREFIX "")

I get:

""xsb_vatsim.xpl

as an output file.

If I use:

SET_TARGET_PROPERTIES(xsb_vatsim PROPERTIES PREFIX)

I get:

SET_TARGET_PROPERTIES called with incorrect number of arguments

any thoughts on how I can correct this?

Thanks,

Wade