Relation modified while in use

Hello,

I obtain:

java.sql.SQLException: ERROR:  RelationClearRelation:
relation 94191976 modified while in use

While executing:

select idzone,access_time,access_speed from
results_488131770, zones where ( ((date > '2001-11-07' )
or (date = '2001-11-07' and time >= '03:29:36')) and
((date < '2001-11-07' ) or (date = '2001-11-07' and time
<= '06:29:36')) ) and idhost=idagent;

Sometimes (not always), when a

VACUUM ANALYZE;

is running in parallel.

Is this known as a driver issue? Is it fixed? Is fixed driver compatible
to the old (7.0.3) backend?

Is it a (7.0.3) backend bug? (Probably, the answer is yes.) Is it fixed
on 7.1? If I must update the backend, what is the smoothest way (least
down time) ? (Probably not the right list, I know. Could someone forward
the mail to the right one, or tell me which one is best, please?)

Thank you very much.

Antonio Fiol