Text on signs isn't consistent across resource packs

Text that reaches across a sign in one resource pack doesn't reach across the sign in default.

For example, using Soartex Invictus, a sign reads

"Why can't I make a
server as awesome
as this?"

However, on the default textures it reads

"Why can't I make
server as
as this?"

Soartex: http://i.imgur.com/5oAcZGF.jpg
Default: http://i.imgur.com/mjQ2Wry.png

Just tested with Defscape: http://i.imgur.com/5vH0PNU.png

The text varies across packs.