We prove that for a suitable associative (real or complex) algebra whi
ch has many nice algebraic properties, such as being simple and having
minimal idempotents, a norm can be given such that the mapping (a,b)
bar arrow pointing right ab + ba is jointly continuous while (a, b) ba
r arrow pointing right ab is only separately continuous. We also prove
that such a pathology cannot arise for associative simple algebras wi
th a unit. Similar results are obtained for the so-called ''norm exten
sion problem'', and the relationship between these results and the nor
med versions of Zel'manov's prime theorem for Jordan algebras are disc
ussed.