These are the packages that would be merged, in order:

Calculating dependencies /!!! Digest verification failed:
!!! /usr/portage/dev-util/dialog/dialog-1.1.20070227.ebuild
!!! Reason: Filesize does not match recorded size
!!! Got: 1468
!!! Expected: 1470
... done!
[ebuild     U ] media-libs/libpng-1.2.18 [1.2.16] USE="-doc" 610 kB
[ebuild     UD] dev-util/dialog-1.0.20060221 [1.1.20070227] USE="unicode -examples" 330 kB
[ebuild   R   ] sys-devel/gcc-4.1.2  USE="fortran mudflap* nls (-altivec) -bootstrap -build -d -doc -gcj -gtk (-hardened) -ip28 -ip32r10k (-multilib) -multislot (-n32) (-n64) -nocxx -objc -objc++ -objc-gc -test -vanilla" 0 kB

Total: 3 packages (1 upgrade, 1 downgrade, 1 reinstall), Size of downloads: 939 kB

*** Resuming merge...
>>> Verifying ebuild Manifests...

!!! Digest verification failed:
!!! /usr/portage/dev-util/dialog/dialog-1.1.20070227.ebuild
!!! Reason: Filesize does not match recorded size
!!! Got: 1468
!!! Expected: 1470