upgrade frenzy

[Yves de Champlain]

I have a few problems with port upgrade.

First, why does it uninstall ports.  Isn't it supposed to just  
deactivate old ports ?

Second, things get a little weird (just the last lines of "port -f  
upgrade pango") :

Warning: Uninstall forced.  Proceeding despite dependencies.
--->  Deactivating cairo 1.2.4_1
--->  Uninstalling cairo 1.2.4_1
--->  Verifying checksum(s) for pkgconfig
Error: No checksum set for pkg-config-0.21.tar.gz
Error: Target com.apple.checksum returned: Could not open file: / 
Users/Shared/dports/distfiles/devel/devel/devel/devel/devel/devel/ 
devel/devel/devel/pkg-config-0.21.tar.gz
Error: The following dependencies failed to build: render pkgconfig  
xrender
--->  Unable to uninstall pango 1.14.2_0, the following ports depend  
on it:
--->    gtk2
--->    libgnomeprint
--->    gtk2
Warning: Uninstall forced.  Proceeding despite dependencies.
--->  Deactivating pango 1.14.2_0
--->  Uninstalling pango 1.14.2_0
--->  Verifying checksum(s) for pkgconfig
Error: No checksum set for pkg-config-0.21.tar.gz
Error: Target com.apple.checksum returned: Could not open file: / 
Users/Shared/dports/distfiles/devel/devel/devel/devel/devel/devel/ 
devel/devel/devel/devel/pkg-config-0.21.tar.gz
Error: The following dependencies failed to build: Xft2 pkgconfig  
xrender render cairo

Ports get uninstalled one by one, following dependencies, but  
everything jams on pkgconfig because category is getting stacked up  
somewhere.

yves