The following program:
val _ = print (OS.FileSys.fullPath "/usr/src/linux/drivers" ^ "\n")
prints "/usr/src/kernel-source-2.4.19" on my system, when it should  
print "/usr/src/kernel-source-2.4.19/drivers".
(As /usr/src/linux is a soft link to kernel-source-2.4.19.)
--
                                     Niklas