Everything was working fine when suddenly the 1's go missing for the labels: http://imgur.com/VxWAM6K (it should say: 5128254310, but it's missing all the 1's)
I've made no other changes to the KML, it just stopped showing 1's. I can even go into the label and change it to anything, and it systematically removes the 1's.
I’ll add that this is actually a bug in Chrome 45 (and only happens in that version). All other browsers (including Chrome 44) work fine. We are working around the bug for now, but expect it to eventually be fixed in Chrome.
In your code, you can try to double the size of your font (assuming it’s linear) and set the scale to 0.5 to work around the issue.