Excel 2000 on WinNT platform.

I'm trying to insert some code into a specific worksheet in a
workbook. The code is shown he

Set VBCodeMod = ActiveWorkbook.VBProject.VBComponents(ActiveWorkbo ok.Worksheets("Images").CodeName).CodeModule
StartLine = VBCodeMod.CreateEventProc("Change", "Worksheet") + 1
VBCodeMod.InsertLines StartLine, "Msgbox ""Hello World"",vbOkOnly"

(sorry about the line break...)

Once the code executes the CreateEventProc line I get an error box
that says:

Run-time error '-2147417848(80010108):'
Automation error
The object invoked has disconnected from its clients.

Then Excel is hosed... have to quit and reopen.

The interesting part is if I try to insert some code into ThisWorkbook
everything works just fine. I've alse tried just using InsertLines
without a CreateEventProc call. Same effect. Any ideas???