OK, so managed to get Pier installed into the squeak 4.1 one-click distribution and clicked on blog. I can leave a comment but I get stuck in a loop where I can't cancel the comment request. Has pier, especially the blog component, been tested with the 4.1 one click distribution?
Some ways of registering Pier:
1) PRPierFrame registerAsApplication: 'pier' kernel: PRDistribution new kernel.
2) PRPierFrame registerAsApplication: 'pier' kernel: (PRKernel named: 'aSimpleKernel').
3) PRPierFrame registerAsApplication: 'pier' kernel: (PRKernel new root: (PRPage new title: 'test title'; contents: 'Pier on Seaside 3.0'; name: 'testPage'); name: 'aVerySimpleKernel').
AFAIK all Pier development takes place on Pharo - might be worth trying the Pharo Seaside30rc and seeing if you have the same problem there.
Nick