VS Server Explorer - column does not appear in the Columns list?

Question

For an existing table in SQL compact 4 db

Added a column of Type Bit, click OK but it does not show up in DataEditor nor in the list of columns But it's there in the Table Schema editor

I am able to edit the data using ErikJ's SQL compact toolbox but curious about what rules i may have violated here to cause this behavior ???

FYI - the column name is IsSys which is not shown, i added other bit columns for test and they appear in the columns list !

UPDATE - sql is below, IsSys and IsSystem both don't show up in Server Explorer list of columns or in ServerExplorer's DataEditor, though they show up in Table Schema Editor

CREATE TABLE [ProblemTable] (
  [AttrId] int NOT NULL  IDENTITY (30,1)
, [AttrTypeId] int NOT NULL
, [SelText] nvarchar(50) NOT NULL
, [SeqNum] int NOT NULL DEFAULT 9999
, [UpdatedBy] int NOT NULL DEFAULT 1
, [UpdatedAt] datetime NOT NULL DEFAULT getdate()
, [AttrKey] nvarchar(40) NOT NULL
, [IsEnabled] bit NOT NULL DEFAULT 1
, [IsShown] bit NOT NULL DEFAULT 1
, [IsSys] bit NULL DEFAULT 0
, [IsSystem] bit NOT NULL DEFAULT 0
);
GO

Answer 1

Interesting - This appears to be "by design" - likewise table names starting with __Sys are filtered out. As stated in the article in spanish linked above, do not use IsSys for column names!