Erggg.. I should read before I post. Found the answer to my question in the following post: http://www.asp.net/Forums/ShowPost.aspx?tabindex=1&PostID=247485 Just had to change the order of the following in the UpdateTag() sub to:

Dim dbParam_taggerName As System.Data.IDataParameter = New System.Data.OleDb.OleDbParameter
dbParam_taggerName.ParameterName = "@taggerName"
dbParam_taggerName.Value = taggerName
dbParam_taggerName.DbType = System.Data.DbType.String
dbCommand.Parameters.Add(dbParam_taggerName)
Dim dbParam_tagText As System.Data.IDataParameter = New System.Data.OleDb.OleDbParameter
dbParam_tagText.ParameterName = "@tagText"
dbParam_tagText.Value = tagText
dbParam_tagText.DbType = System.Data.DbType.String
dbCommand.Parameters.Add(dbParam_tagText)
Dim dbParam_tagDateTime As System.Data.IDataParameter = New System.Data.OleDb.OleDbParameter
dbParam_tagDateTime.ParameterName = "@tagDateTime"
dbParam_tagDateTime.Value = tagDateTime
dbParam_tagDateTime.DbType = System.Data.DbType.DateTime
dbCommand.Parameters.Add(dbParam_tagDateTime)
Dim dbParam_tagID As System.Data.IDataParameter = New System.Data.OleDb.OleDbParameter
dbParam_tagID.ParameterName = "@tagID"
dbParam_tagID.Value = tagID
dbParam_tagID.DbType = System.Data.DbType.Int32
dbCommand.Parameters.Add(dbParam_tagID)

And now everything works. WTF? lol I'll get the hang of this yet.