Ive noticed that a lot of people are having this problem. I was too when i was trying to update my Urpmi FTP Source from their website (http://easyurpmi.zarb.org
). I tried deleting the .LOCK & .RPMLOCK files but it wouldnt allow me to. this is what i did to get past it and update my FTP sources. (BTW- Im on Mandrake 10.0)
I created a new user just called "rootuser" and gave it access to the root group. logged in with that user and ran the FTP addy updates in console using Super User as my rootuser and it worked fine without having to delete those .lock / .rpmlock files. now the new sources are listed in my RPMDrake list so i can use the GUI update program to get all the new files rather than having to use urpmi from console. I imagine the update will still work from another distro.
after trying again to do this from my regular user account i realized this. it didnt matter that i made a root account. its just that i restarted my computer. so thats all i had to do. if your urpmi is locked, just try restarting your computer.