RE: multiple origin ASes

Abha has already asked this question, but let me ask it a
slightly different way:

RFC 1930, section 7 states:

: 7. One prefix, one origin AS
: Generally, a prefix can should belong to only one AS. This is a
: direct consequence of the fact that at each point in the Internet
: there can be exactly one routing policy for traffic destined to each
: prefix. In the case of an prefix which is used in neighbor peering
: between two ASes, a conscious decision should be made as to which AS
: this prefix actually resides in.
:[part about aggregation snipped]

The real question is, has a prefix originated by more than one AS
ever caused anyone any serious operational issues? The only one
that springs to mind is the difficulty in getting ahold of the actual
"owner" network.