>OpenGL Error: DLL Loader couldn't find/open VBoxOGLpackspu.so

This message is from libGL and not Trinity. I see messages like 
this whenever libGL is called indirectly from Trinity.

For example, on my system, running 'tdecmshell opengl' results in 
libGL spew.

Try running the screen saver module directly in a terminal:

tdecmshell screensaver

Then you'll see the errors and warnings directly and won't have to 
wade through the xsession-error log.

Despite the complaints by libGL, the screensaver module should not 
crash. Can you capture a kcrash backtrace?

Darrell