How to start workflow, designed in Sharepoint Designer, by adding/changing folder (not document)?

Hi,

I build wf and bound it to specific library document.

Now, I want wf to start when the new folder is added or its property is changed.

It does not happen.

I created ny custom content type, when the parent folder - on it wf does not start either.

Maybe there some flag that I should to set - to enable starting workflow on specific content types

Thanks

Eli Ofek
Are you getting any errors in your SharePoint logs from your workflow

I found that sometimes when workflows weren't starting when I expected them to, it was because there was an error in the workflow during start, and it didn't warn me through the user interface. I could only see the errors in the logs. It's very hard to debug.
XNAConfused
Where do I see the logs

I am writing to "log to hostory" log but the only place I see it is inside workflow status

Ii want to mention that the work flow is started OK on doc event, but is not started on folder event.
How to start workflow, designed in Sharepoint Designer, by adding/changing folder (not document)?