A document library with custom properties, such as "Year". In
itemAdded event receiver, with code snippet like the following:

item = web.Lists[properties.ListId].GetItemById(properties.ListItemId);
item["Year"] = "2007";
item.Update();

Above code works fine when using "Upload Multiple Documents" from the
"Upload" menu; however, if using "Upload document" from the same menu,
after browsing the file, on the editform page to edit properties,
click on the OK then it gives a error message like the following:

Also please note during debugging mode, the event receiver code does
not generate any exceptions, so the problem lies after the event has
been processed.

Anyone has any suggestions on this?