Illustrator CS5 and Adobe Reader X shared PDF rendering Bug

[capellan]

Hi,

Recently I found this shared PDF rendering bug
by both Adobe products: Illustrator CS5 and
Reader.

Look at the attached files.

If you look the PDF file in Illustrator CS4
or Foxit Reader or Preview (from MacOS X)
these square clipping boxes around the words
"La Tormenta" are not found.

Please compare the Xara file (the source)
with the pdf display in these recent Adobe
versions. Did Adobe simply "changed" or actually
"fixed" the pdf rendering engine?

Which person in Adobe had the strange idea of
clipping these vector objects with a box???

How could I view these PDF as intended using
CS5 and Reader X?

Thanks in advance!

Alejandro