Many users who have tried to use redsn0w 0.9.15 beta 1 for restore to iOS 6 and keep the baseband intact they met 2601 error during the restore process, and everything has to do with iTunes. It seems that on Windows this process does not work, on Mac there are no problems and you can do nothing but wait until a new version of redsn0w is going to be released. Probably tomorrow or in the following days it will be available and will solve the respective problem which, I repeat, only affects people using redsn0w 0.9.15 on Windows OS.
