InfoPath Dev

I am getting the "form has closed" error whenever I add any SharePoint code at all to my LoadingEventHandler for my InfoPath form.  I have been able to do non-SP stuff such as modify the value of a field, but as soon as I add in code like:

SPSite site = SPContext.Current.Site;

or

using(SPSite siteCollection = new SPSite("...url"))
{
}

Once code like that is added, I get that "form has closed" error upon opening the form.  Am I missing something, a dll reference or something?  Should this work?

I looks like I just needed to set the trust level to Full Trust to get it to execute SP code.