Sorry for the double post. I can’t believe there’s no way to delete my own posts.
That’s what I expect and I’m happy to hear you aren’t having problems.
Usually, that third number (x in 5.2.x) is for bug fixes only. Projects won’t change anything that might break code without changing the second number (5.1 -> 5.2).
I’ve learned from experience to avoid updating packages outside of the vendor package manager (aptitude, in this case). It’s much easier to keep up with security and bug fixes that way. Debian hasn’t backported PHP 5.3 to Lenny, so the only way to get it is to update the entire operating system to Squeeze. That’s a big undertaking and I’d like to avoid it if I can do so safely.