like dsl, tc has two screens, which i'll refer to as caf1 (ctrl alt f1) and caf2 (ctrl alt f2) for the shortcuts.
what i've done before is quit x to go back to caf1 then startx & which lets me use caf1 while xwin is caf2.
another thing i've done is switch to caf1 then ctrl-c to close x, then startx &
however, in trying these out, i found that simply switching to caf1 then caf2 will make it impossible to access anything in tc. the screen will change all one color (depending on settings, all white or all black) and no keyboard shortcuts seem to do anything then, after that there isn't even a way to get back to caf1, which is the screen you have just before x starts anyway. i tried ctrl alt backspace, and ctrl c, those didn't help.
i have only tried this on one computer, but it's not a problem i've had on this computer before. i realize as bugs go, this is probably not the most interesting, but i wish i knew more about it.