I worked in a big company where the extensions had 5 numbers and never heard anybody referring to an extension like 44349 like forty four thousand three hundred and forty nine but always like four four three four nine.
I accidentally had my 1.2.10 box say 10-digit phone numbers as number when I began to play with Asterisk. No problem there. Is there any error message when you try to say large numbers?
1.2 has a long range of subversions. (0-16). I also learned of some subtler problems that only occur on a certain Linux build.