pdflatex 1.20 :pdf inclusion pdf version problem

Hello, All:

I am new to this field, so please forgive me if the following question
is
straightforward.

I am updating my pdflatex from 1.11b to 1.20a-rc3-2.1.
The source code is from:
ftp://dante.ctan.org/pub/tex/systems/unix/teTeX-beta/  (Yes, most recent
beta version)

I am fine of going through the compiling steps. And pdflatex is ready.
But, after running pdflatex, I encountered the following message:

------------------------------------------------------------------------
----

pdflatex pdf inclusion: found pdf version <1.4> , but at most version
<1.0>
allowed
------------------------------------------------------------------------
----


which was NOT present when i was using pdflatex 1.11b.

I also checked pdftex.def: it is the current version as:
------------------------
[2002/06/19 v0.03k }
-------------------------


Greatly appreciate any helps!

Best,
 
Xiaobin