[Typo3-dev] Strange behaviour with extrep_kickstarter?

[Braulio José Solano Rojas]

Hi!

I've been learning how to develop new extension and I've been using the 
Kickstarter wizard for that task.

After I define my tables and everything I just go to develop. But sometimes, 
I want to return to the design step, for instance if I forgot a field in one 
of my tables.

Easy:
* In the extension manager I choose my extension.
* Within my extension I choose Backup/Delete.
* In Backup/Delete I choose Start New.

Did not know why this was not working all the times.  I discovered that this 
functionality works only if the tables of my extension are not created and 
the extension is uninstalled.  It is not logical for me and it was hard to 
find why I could not return to the extension design sometimes.  For me it 
would make sense that the extension must be uninstalled, but only that.  Why 
the tables need not to be in the database, since when installing extensions 
Update of tables is automatic?

Is this a normal behaviour?  If it is, what's the reason for this?

Best regards (from Costa Rica),

B.

P.S.:  Please be gentle since I am starting to learn TYPO3 development.