Zipalign issues

Hi guys, 

So I’m building for release right now and the last hurdle (I hope) is zipalign. I use the code specified here -> http://developer.android.com/tools/publishing/app-signing.html#setup <- in cmd and zipalign tells me the following:

Output file ‘myapp.apk’ exists

Then when I check for verification it says verification failed. Google play also tells me the app is not zipaligned…

Any ideas? Surely this is something everyone is going through?

M

EDIT: I think I’m getting the input and output file naming section wrong. If the input is myapp.apk shouldn’t the output also be myapp.apk? I thought it was supposed to overwrite it, especially if I use the -f flag?