automatic upgrade failed from 2.7 to 2.7.1

update:
I had a 2.7 installation locally on my computer running on xampp.
so I replaced the themes, plug-in and uploads folder and the database with the ones that are online… and the page loaded (even though if i try to navigate inside the site, it tries to go to the one online).
the pw-admin page, though, gives me this error:

Warning: Cannot modify header information – headers already sent by (output started at C:\Program Files\xampp\htdocs\wordpress\wp-content\themes\nic-pixel1\functions.php:83) in C:\Program Files\xampp\htdocs\wordpress\wp-includes\pluggable.php on line 850

any clue?

not getting any answers, I actually figured it out myself.
Hopefully I am the only unlucky one out there who had this problem, but i thought I’d share how i fixed it with the next unlucky ones to come…

It’s actually pretty simple:
-If you didn’t back up (like myself) just do it now: both the database and all your files.
-Clear the database and all the files.
-Install 2.7.1
-Check that it works (even though I don’t see why it shouldn’t)
-Upload your themes, plug-ins, and the uploads folder.
-Load the database you backed up previously.
-Done!

I actually found a quicker, less orthodox way as well (i suggest using it only as a last resort):
-backup the wp-content folder
-delete all folders
-upload 2.7.1
-run the install script, it will tell you that you already have WordPress installed, because you didn’t clear the database. nevermind that.
-Upload your backed-up wp-content.
-Now log into the admin… it should work. i tested all functions and they seem to work just fine.