How do I set the account used for ical reminders?

Hello folks,

On my wife's computer we have OS X Lion.

She has two email accounts loaded on Mail, using IMAP. These are Gmail accounts. I will refer to them as account #1 and #2

In iCal she has calendars loaded from Gmail account #1.

We have noticed that all her iCal event reminders are being sen to account #1 using account #2 for the sending. Even though the event is on a Gmail Calendar on account #1.

She has no calendars loaded from account #2 (as she does not use calendars on that Gmail account).

Neither of us can figure out why or who iCal is sending out reminders via her second gmail account, for appointments set in the calendar of her #1 email account. We can not see why logically iCal and/or Mail is linking these accounts in this way.

We'd like to have it so that the reminders are only sent using account #1.

Can anyone tell me how or why this is occurring, and what I can do about it?

Thank you so much,

Jonathan