Can't copy paste to usb pendrive on peppermint one 010411

The latest version of Peppermint One OS released 4th january 2011. I installed it in two computer. I like to recommend it on more computer. I recommend it to many place like my friend, colleague, shop etc. I am going to install it to three more computer. But before that, I am facing a problem on both computer. I can't copy anything to my regular usb pendrive. I think it is permission peoblem. I tried it in sudo mode, result is same. Can't copy paste anything to that usb device. Is this normal?

After searching through peppermint os forum I found a topic titled error copying files [SOLVED]. That thread said that it is PCManFM issue. So, you should try other 'File Manager' to manage files and folder.Forum members suggested to use emelFM and dolphin. I checked wikipedia and read the page 'File Manager'. But I have not taste any of them yet.