[CMake] ctest problem?

[John Biddiscombe]

couldn't change working directory to "/local/testing/cmakebuild/cscsnightly_vtk/bin/Release": no such file or directory
Error in startup script: The Tcl interpreter was probably not able to find the VTK packages.  Please check that your TCLLIBPATH environment 
variable includes the path to your VTK Tcl directory.  You might find it under your VTK binary directory in Wrapping/Tcl, 
or under your site-specific "/usr/local/lib/vtk/tcl" directory.  
[...snip long error stuff]

I get the above whenever I try to run tests on the linux box (no problem on windows). The ctest program is trying to change into a "Release" sub directory. 
cmake never creates Release/Debug directories under linux, so I don't know why this is happening.

Any ideas? 

JB