Yes, unfortunately that's one detail right now is that zend doesn't support 5.5 yet.  We have a few options here though:

1.  We can change your system's PHP to 5.4
2.  We can grab php-5.4 from their site and specify the new path to the binary
3.  In v2 we hope to handle all of this grunt work for you so you don't have to

If you need help with option #1 or #2, just let me know if that's the route you'd like to take.  Neos v2 is due to be released within the 1.5 weeks or earlier.

     Best regards,

syntaks