Delete bin folder, redownload packages from the minecraft.exe and then try again :biggrin.gif: You might have done something baaaaaad to you're folder :biggrin.gif:
Use INVEdit for windows or INVGrid for Mac. You can give yourself running water and running lava and then scoop them up. Make sure not to scoop up the source block however.
Quoted for Truth
Gotta love those moments!
You probably did it wrong.