Question: Can I use access 2007 VBA references with impunity (specifically, as far as the base language and old com interfaces are concerned) to develop VBA based solutions for access 2003?

Or is there some new/modified syntax added to the language that I need to be aware of?

Has the object model been enhanced drastically in office 2007?

Any other caveats?

Answer: 
There is some new properties, methods and objects in Excel 2007. 

However, most programs in Excel 2003 works well in Excel 2007

There are few stuff from VBA Excel 2003 that doesn't works at Excel 2007.

I've found 4 issues.

* "Chart.Add" give automation error in Excel 2007 when there are more than 1 cell selected
* Error don't reset by itself, it's necessary uses Err.clear before command that could
be release a error.

```
        On Error Resume Next
        Intruction_That_Could_be_buggy_1
        if Err.Number <>0 Then
             Err.Clear     '  <<<<==== This command is necessary
             Intruction_That_Could_be_buggy_2                  
             if Err.Number <>0 Then
                   ....

```
* Range(...).Paste(xlFormulas) now stops when exists a possible name conflict,
it's necessary to use 

```
    Application.displayalerts = False
    Range(....).Paste(xlFormulas)
    Application.displayalerts = True

```
* Several hotkeys like Alt+N are reserved in Excel 2007. 
Application.Onkey("%n","rotina") doesn't works in that case. 
Now it's many ribbon shortcut in the ALT+Letra style.
I cannot found any way to suppress this behaviour.
It should be used other hotkey instead.
If you are compiling your accdb/mdb to accde/mde, you want to make sure you compile them in the same version as your main applicaiton. I've had some trouble using Access 2003 MDE's with Access 2007 (and obviously vice versa).