Vaccum and 24/7/365 database

Hi all,
    we use postgresql 7.2 for a data logging/supervisor application running
24 hours a day, 7 days a week and 365 (and 6 hours) a year. Data are
inserted/deleted/updated each 1,5 minutes and for performance reason we
have to vacuum each day some tables. The problem is that vacuum stops
inserts, updates and deletes for the table it performs (well in fact, I
understood this). This way of working for the database does not fit our
needs of 24/7/365 availability. So my question is : is there a way to
get all the things work together (good performances & availability)?

    Thanks a lot.

--
Jean-Christophe ARNU
s/w developer
Paratronic France