ROX_CLIB_VER has to be set before inherit rox, otherwise it does't work. To reproduce: while you have no rox-clib installed, try to emerge systemtrayn - it fails to find rox-clib during compile. Look into rox.eclass.
Indeed, and thanks for the bug! I have fixed this in systemtrayn for now, not sure if this even *can* be fixed in the eclass. If not I'll probably have to update 90% of the rox ebuilds :)
No, it looks like all ROX_LIB_VER, ROX_VER, and ROX_CLIB_VER setting MUST be before the inherit line. Hooray! Thanks very much for the heads-up, I'll leave this bug open to ensure I get every rox package fixed.
There, fixed the order of variables in all rox packages.