So you are emailing the iCal field in a regular QuickBase notification? As in just putting the field in the Custom Message like [my iCal field]? I just tested this myself and my subject worked fine. My dates were correct, but my times were not until I set them properly. Once I set them correctly in the field it worked for me when the iCal was emailed.
How are your Date/Time fields set up? Are they a formula of some sort? Do you manually enter these? The date is easy to set in there but the time isn't as straight forward as it just leaves you a blank space there.
Also, are you doing a lookup of the ical field anywhere? I would avoid that at all costs. That is where I am getting errors with this. I would send your notification from wherever the iCal field exists, do not look that up. What you need to do is look up the fields you need for your iCal to one central place and then create the iCal there imo.