Thanks, Jaymer. Great info. I finally resolved the issue by removing some '#' and '$' characters from the db table field names. (I don't know if one or both were problems.) As soon as I did this and recreated the AIM objects, everything finally worked.
Original table:
CREATE TABLE [dbo].[RECAP](
[LOGIN_NAME] varchar NOT NULL,
[CREATE_DATE] [datetime] NOT NULL,
[VenName] varchar NULL,
[Ven#] varchar NULL, <-- REMOVED '#', etc.
[Law#] [int] NULL,
[PIC#] [int] NULL,
[Comp] [smallint] NULL,
[APIAStat] varchar NULL,
[LawStat] varchar NULL,
[Pymt#] varchar NULL,
[PymtDt] varchar NULL,
[LawCode] varchar NULL,
[ReconDt] char NULL,
[Missing] varchar NULL,
[Inv#] varchar NULL,
[InvDt] char NULL,
[Inv$] [decimal](18, 2) NULL, <-- REMOVED '$'
[PO#] varchar NULL,
[APIAMsgType] varchar NULL,
[Buyer] varchar NULL
) ON [PRIMARY]