Web Assistant Wizard Problem

I used SQL Server's web assistant wizard to create a
web assistant job. In this job I chosed "When SQL
Server Data Changes" for schedule options. Late, I
don't want this job and by right click web assistant
job I deleted this job.

However, I have a stored procedure which use the same
table with the above deleted web assistant job. Normally,
the stored procedure runs only 1 minute. Today it runs
more than 5 minute and then failed. Here is the error
messages:

++++++++++++++++++++++++++++++++++++++++++++++++++ ++++
Server: Msg 16882, Level 11, State 1, Line 0
SQL Web Assistant: Web task not found. Verify the name
of the task for possible errors.
++++++++++++++++++++++++++++++++++++++++++++++++++ ++++

Please somebody can tell me how can I solve this problem
(or totally delete the above web assistant job).

Thanks.