Sharepoint 2010 document list workflow on updated does not work

Hi All

I have a document library with custom fields in Sharepoint 2010 site, I activate a onUpdated event reciever that chages some fields after a user updates the record on certain situations. the update goes good.

I also have a workflow on the same list that works on on updated (Sharepoint designer wf)

the wf does not fire on update but only on insert

any help

Shlomy