iOs - Events pushed to the _paq queue near Submit time not recorded by Piwik server

Hi guys,
I’ve got a few trackEvents being pushed into the _paq queue in an onClick event of submit buttons/link. These events seems to be recorded fine when I’m on Windows and Android (the usual browsers Chrome, Firefox, IE), but I’ve noticed that on iOS (I’ve tested with Safari on iPhone/iPad and Chrome on iPad), the last event pushed before Submit never makes it to the Piwik server. The event does not show up on the visitor’s log and the next page access (after the submit) is recorded. I’ve tried delaying the submit with a SetTimeOut but this doesn’t seem to help. Have you guys encountered this before? Does anyone know how this can be fixed?
Thanks,
Raphael.