Problem updating AIX 4.3.3 ML0 to ML11 - Error 0503-248

I am trying to apply Maintenance Level 11 to one of our older AIX machines that is currently at ML0. When I try to install the bos.rte.install for ML11 it gives the error 0503-248 stating:

Verifying requisites...
0503-248 installp: Error: A fileset has parts that are different from one or
more of the filesets it supersedes. It is NOT valid for a fileset with
a "usr" part only to supersede a fileset with both "usr" and "root"
parts. A fileset with a "share" part may only supersede another fileset
with a "share" part.
The fileset in error is:
bos.rte.install 4.3.3.80

This error also occurs with the fileset bos.rte.install 4.3.3.81

Anyone know of a way to work around this?

Thanks
D