How can I prevent custom build packages from downgrading

[T <mlist4suntong@yahoo.com>]

Hi, 

How can I prevent my custom build packages from being downgraded, without
applying hold onto them? 

I custom build dvd+rw-tools and nget packages. But whenever I use "apt-get
upgrade", I'll get 

The following packages will be DOWNGRADED:
  dvd+rw-tools nget

What's the best approach to custom build packages so as not to interfere
with apt-get? 

In order not to be overwritten by apt-get, I increased my custom build
packages by .1, like below:

$ apt-cache policy dvd+rw-tools
dvd+rw-tools:
  Installed: 5.21.4.10.8-1.1
  Candidate: 5.21.4.10.8-1

$ apt-cache policy nget
nget:
  Installed: 0.27.1-1.1
  Candidate: 0.27.1-1

But now apt-get insists that I have to downgrade them.

Please help

thanks

tong