Which is why upgrading is costly. When you've tweaked things in 20, 30, 50 heres and theres, writing over them for the next decimal upgrade becomes prohibitive. It's time and money gone completely out of the window. 

>From a consultant's perspective this is great because it ensures you're gonna get paid for a while. Form the point of view of a small publisher, the problem is terrible. 

Liza et al:

I really can’t bear to let this thread go on any longer.  I know what Laura is getting at, and she is absolutely spot on in that thread.  But, I disagree with you about the severity of the problem of unsupported older versions.

• I strongly do not want to see fragmentation in the user community around version releases.  I like you guys.  I want you to keep on for the duration. ;-)
• I really strongly encourage anyone on the 4.5 code base or similar to upgrade as soon as possible.  I have seen what happens when you don’t.  I’ve listened to a lot of arguments from people using an older platform (it’s almost always those who are on the platform that make the argument), but I can tell you it’s in your best interest, and your customer’s best interest, to keep up with current releases, and fix/rebuild anything build on old releases as opposed to trying to protect the investment – it’s definitely a false safety.