[Not repeatable] js errors on login page [1.3.6]

[paulm]

On a clean 1.3.6 install (zen-cart-v1.3.6-full-fileset-10272006)

Firefox (2.0) Error Console complains about:

Fout: syntax error
Bronbestand: http://www.xxxx.xx/index.php?main_page=login
Regel: 37, Kolom: 4
Broncode:
} else {

Fout: update_zone is not defined
Bronbestand: http://www.xxxx.xx/index.php?main_page=login
Regel: 1

I did install a language pack, but switching back to English does not help (in the past I noticed language files sometimes cause js errors).

No idea why it happens and if it causes real problems, but I just noticed it on two fresh installs today.