portupgrade question

[Nagy László]

After running

portupgrade -aP

I get this:

** Listing the failed packages (*:skipped / !:failed)
        ! textproc/linux-expat (linux-expat-1.95.7_1)   (install error)
        * x11-fonts/linux-fontconfig (linux-fontconfig-2.2.3_4)
        * x11/linux-XFree86-libs (linux-XFree86-libs-4.3.99.902_7)
--->  Packages processed: 0 done, 136 ignored, 2 skipped and 1 failed
** Could not clean up temporary directory: Directory not empty - 
/var/tmp/portupgradeibUXCdq2

It ignored 136 packages. Is this safe? How can I know what it ignored 
and why?
Thanks,

   Laszlo