BUG #7756: When upgrading postgis extension get row is too big: size 9272, maximum size 8160

The following bug has been logged on the website:

Bug reference: 7756
Logged by: Regina Obe
Email address: lr(at)pcorp(dot)us
PostgreSQL version: 9.2.2
Operating system: Windows 64-bit, Window 32-bit
Description:

This might be a postgis issue, but I don't know how to debug it since I
don't know where the error is coming from (what table it's complaining about
etc.) and no further detail is given in the logs.

I'm the maintainer of the PostGIS extensions so will be happy to change if
I'm doing something wrong in packaging.

PostGIS to upgrade from 2.+ to 2.1 and any interim revision of 2.1 only has
one script which are copied to various versions to support the version
naming of extensions since this creates too much junk I have a hack
extension script to allow me to upgrade PostGIS 2.1 to any 2.1 super r.
Which basically yoyos between 2.1.0 and 2.1.0next and back to 2.1.0

I can upgrade for about 3 times before getting the error and its pretty
consistent. 3 times for the postgis one (postgis_topology one I can go on
for infinity it seems with the same exercise). I'm pretty sure it's
something in our raster machinery tripping it up since if I cut that out,
the extension upgrade can be done indefinitely. Of course our raster
machinery is the piece that is the most volatile and complicated in
structures.

I have the bug more described on this ticket:
http://trac.osgeo.org/postgis/ticket/1959

I've tried on 9.1 and older 9.2 installs and recently upgrade to 9.2.2 with
same issue.