I've got the same problem. Here's my software-center logfile. Here's what I did: I installed LIMBO from the Humble Indie Bundle and tried to write a review.
** Attachment added: "software-center logfile" https://bugs.launchpad.net/ubuntu/+source/software-center/+bug/778070/+attachment/3177390/+files/software-center.log -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to software-center in Ubuntu. https://bugs.launchpad.net/bugs/778070 Title: Failed to submit report/review in software-center Status in “software-center” package in Ubuntu: Confirmed Bug description: Binary package hint: software-center Trying to submit a report or review in the software-center I get an error-message: Failed to submit report/review though I am logged in to my ubuntuone-account. ProblemType: Bug DistroRelease: Ubuntu 11.04 Package: software-center 4.0 ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2 Uname: Linux 2.6.38-8-generic x86_64 NonfreeKernelModules: nvidia Architecture: amd64 Date: Thu May 5 21:21:05 2011 ExecutablePath: /usr/share/software-center/report_review.py InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1) InterpreterPath: /usr/bin/python2.7 PackageArchitecture: all ProcEnviron: LANGUAGE=de_DE:en LANG=de_DE.UTF-8 SHELL=/bin/bash SourcePackage: software-center UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/software-center/+bug/778070/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp