Error Executing "port -R upgrade pango"

I noticed that pango got updated. So I perform the following: % sudo port -R upgrade pango ---> Deactivating pango 1.16.1_0 ---> Fetching pango ---> Verifying checksum(s) for pango ---> Extracting pango ---> Applying patches to pango ---> Configuring pango ---> Building pango with target all ---> Staging pango into destroot ---> Packaging tgz archive for pango 1.16.1_1 ---> Installing pango 1.16.1_1 ---> Activating pango 1.16.1_1 ---> Cleaning pango ---> Unpacking tgz archive for pango 1.16.1_1 ---> Deactivating pango 1.16.1_0 Error: Deactivating pango 1.16.1_0 failed: Active version of pango is not 1.16.1_0 but 1.16.1_1. What's up w/ the error? Is this a bug?