Also,

I have a lot of these transactions in my system log

2010-11-17 08:01:42,390 INFO mojoPortal.Web.WebTaskManager - deserialized WebTaskManager task
2010-11-17 08:01:42,390 INFO mojoPortal.Web.WebTaskManager - Queued WebTaskManager on a new thread
2010-11-17 08:01:42,500 INFO mojoPortal.Business.WebHelpers.IndexWriterTask - deserialized IndexWriterTask task
2010-11-17 08:01:42,500 INFO mojoPortal.Business.WebHelpers.IndexWriterTask - Queued IndexWriterTask on a new thread
2010-11-17 08:02:32,671 INFO mojoPortal.Business.WebHelpers.IndexWriterTask - started IndexWriterTask task
2010-11-17 08:02:42,578 INFO mojoPortal.Web.WebTaskManager - started WebTaskManager task
2010-11-17 08:20:52,843 ERROR mojoPortal.Web.Services.PayPalIPNHandler -
System.NullReferenceException: Object reference not set to an instance of an object.
at mojoPortal.Web.Services.PayPalIPNHandler.HandleRequest()
2010-11-17 08:23:10,046 INFO mojoPortal.Web.WebTaskManager - deserialized WebTaskManager task
2010-11-17 08:23:10,062 INFO mojoPortal.Web.WebTaskManager - Queued WebTaskManager on a new thread
2010-11-17 08:23:10,187 INFO mojoPortal.Web.EmailMessageTask - Queued EmailMessageTask on a new thread
2010-11-17 08:23:10,234 INFO mojoPortal.Web.EmailMessageTask - deserialized EmailMessageTask task
 

So I tried to manually post 1 IPN using the URL specified in PayPal and the autogenerated message that PayPal provided and when I looked at the system log I received the same error

2010-11-19 11:12:54,390 ERROR mojoPortal.Web.Services.PayPalIPNHandler -
System.NullReferenceException: Object reference not set to an instance of an object.
at mojoPortal.Web.Services.PayPalIPNHandler.HandleRequest()
 

I am wondering if it has anything to do with my event titles.  I have added html img tags to the titles in order to show the picture of the class that they are painting. 

http://tipsycanvas.brinkster.net/Services/PayPalIPNHandler.aspx?mc_gross=70.00&protection_eligibility=Eligible&address_status=confirmed&item_number1=a2c43f98-88e9-45d7-81b7-c584b7ee1235&tax=0.00&item_number2=a2c43f98-88e9-45d7-81b7-c584b7ee1235&payer_id=AL5EFBAYYHKCG&address_street=123 Test Address&payment_date=06:32:19 Nov 19, 2010 PST&payment_status=Completed&charset=windows-1252&address_zip=30620&mc_shipping=0.00&mc_handling=0.00&first_name=FirstName&mc_fee=2.33&address_country_code=US&address_name=FirstName LastName&notify_version=3.0&custom=76eadadf-de78-47ce-b2bc-04c20e4eba11&payer_status=unverified&business=paint@tipsycanvas.com&address_country=United States&num_cart_items=2&mc_handling1=0.00&mc_handling2=0.00&address_city=Bethlehem&verify_sign=AWYxjS6LEFCeGqJDu35ZiF0NsD2FACkEWokmM85tIb2oQZBnS8tJQ10q&payer_email=scoobyservtoo@msn.com&mc_shipping1=0.00&mc_shipping2=0.00&txn_id=83V59194UP074063R&payment_type=instant&last_name=LastName&address_state=GA&item_name1=Snowman<br /><img src="/data/sites/1/images/snowman.jpg" width=100><br />7PM-10PM - 12/5/2010&receiver_email=paint@tipsycanvas.com&item_name2=Snowman<br /><img src="/data/sites/1/images/snowman.jpg" width=100><br />7PM-10PM - 12/5/2010&payment_fee=2.33&quantity1=1&quantity2=1&receiver_id=BMKPBYSWGWYWA&txn_type=cart&mc_gross_1=35.00&mc_currency=USD&mc_gross_2=35.00&residence_country=US&transaction_subject=76eadadf-de78-47ce-b2bc-04c20e4eba11&payment_gross=70.00

Still no luck.. I tried it the following ways.

<?xml version="1.0" encoding="utf-8" ?>
<PayPalIPNHandlerProviders>
<providers>

<add name="STSEventsPayPalIPNHandler"
type="sts.Events.Web.Helpers.PayPalIPNHandlerProvider, sts.Events.Web.UI"
description="Source Tree Solutions Event Calendar Pro PayPalIPNHandlerProvider" />

</providers>
</PayPalIPNHandlerProviders>

<?xml version="1.0" encoding="utf-8" ?>
<PayPalIPNHandlerProviders>
<providers>

<add name="PayPalIPNHandlerProvider"
type="sts.Events.Web.Helpers.PayPalIPNHandlerProvider, sts.Events.Web.UI"
description="Source Tree Solutions Event Calendar Pro PayPalIPNHandlerProvider" />

</providers>
</PayPalIPNHandlerProviders>

<?xml version="1.0" encoding="utf-8" ?>
<PayPalIPNHandlerProviders>
<providers>

<add name="PayPalIPNHandlerProvider"
type="sts.Events.Web.Helpers.STSEventsPayPalIPNHandler, sts.Events.Web.UI"
description="Source Tree Solutions Event Calendar Pro PayPalIPNHandlerProvider" />

</providers>
</PayPalIPNHandlerProviders>

I think that I am breathing a sigh of relief.  I just made a new order and I saw both the IPN and the PDT transaction in the Cart Log.  Thank you so much for your help. 

I am still working on my email confirmation functionality, but I got the password reminder email to work. 

Thanks for the Kudos of my site, and for all your help.  It is actually my wife's business and I have been wanting to make it a dynamic site for about a year (I've been making static PayPal buttons and a HTML calendar every month).  MojoPortal's calendar is the perfect tool for a small business start up without the capital to pay a developer!!!

The only features that I would really like to see is the ability to throw a thumb nail image into the Event Title(or just a separate image button that would generate it's own HTML) so that you don't have to write the HTML tag, and the ability to use files located under "/data/sites/1/" on every site.  I would try a virtual directory for the second site, but my hosting doesn't allow virtual directories in IIS.

Thanks again,

Russell