Why does iCal delete my email alert option after update/syncing?

I am running Lion (OS X 10.7.4), and I never had this problem with iCal prior to updating from Snow Leopard.

This problem is becoming more and more persistent, and more maddening.

I have my iCal set up to sync with my gmail calendar.

Upon creating an event in iCal, a seemingly random 'message' alert is there at default. Sometimes it says that the message will be an alert "2210" minutes prior to the event, sometimes it says the day before at a particular time, etc. ALWAYS the default is a message of some kind.

When I attempt to change when the message occurs, OR change the type of alert to an email, for example, the changes are completely reverted back to whatever I changed it from as soon as iCal updates/syncs.

So, it will go something like this:

- Make event

- Attempt to change message alert to email alert (so that I will get an email in my inbox to remind me of the event)

- iCal says "updating", and immediately thereafter the email alert I had set has changed back to the message alert that was there prior.

This also occurs when I attempt to add additional alerts such as emails or messages.

I haven't been able to find much information about this bug save for one forum that I can now not locate.

I would realllly appreciate some help!

Thank you!