amd64 - probs with libs

[michael <cs@networkingnewsletter.org.uk>]

I've an application which when I run gives 


error while loading shared libraries: libXext.so.6: cannot open shared
object file: No such file or directory


but yet the files are available:

mkb@amd64:~/pave$ file /usr/lib/libXext.*
/usr/lib/libXext.a:        current ar archive
/usr/lib/libXext.so:       symbolic link to `libXext.so.6.4.0'
/usr/lib/libXext.so.6:     symbolic link to `libXext.so.6.4.0'
/usr/lib/libXext.so.6.4.0: ELF 64-bit LSB shared object, AMD x86-64,
version 1 (SYSV), stripped


any ideas???

thanks, M ichael