#1 SQL error on Calendar page

[Anonymous]

Fresh install : .94b
Upgraded with : .941b

When a user accesses the Calendar plugin it says:
--------------------------
The following query failed:
select id, date_format(tstart,'%Hh%i') as h,
time_format(duration,'%Hh%i')
as dur, title, comment, projectID as pid, peopleID as
uid from calendar
where to_days(tstart)=to_days(20020401) order by
tstart asc;
Table 'opt.calendar' doesn't exist
--------------------------
This error occured while XXXXXXXXXXX was accessing
/opt/main_menu/Plugins/calendar/mainFrame.php?
...
GET variables:

POST variables:

User Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows
NT 5.0)