libxml warnings while upgrading squeeze -> wheezy

[Itay <debian@itayf.fastmail.fm>]

Hi,

During the upgrade I got many times the following warning:

	program compiled against libxml 208 using older 207

Shooting in the dark I did:

# aptitude show libxml2
Package: libxml2
State: installed
Automatically installed: no
Multi-Arch: same
Version: 2.8.0+dfsg1-7+nmu2
...

I have no idea what is libxml so I don't even no if I was looking 
at the right place.
And can't figure out the correspondence between 'libxml 208' and the 
version number shown by aptitude.  (If there is any.)

Should I be concerned?

Thanks in advance,
Itay