Dialogs not showing up, question on dialogs and data-dom-cache="true"

Dialogs not showing up, question on dialogs and data-dom-cache="true"

JQM1.2.0 Beta
JQ 1.8.1

On my page there is a edit-dialog. When testing at some point it stopped showing. Then suddenly I only saw a black page (theme a), but the dialog was missing. I read the docu and hope to have understood correctly that I need to set  data-dom-cache="true". Since I changed it I wasn't able to reproduce the error, but because the error was not always reproducible in the first place, please, can someone confirm that the data-dom-cache statement missing was the probable cause of the problem? Am I misunderstanding something?

Thanks

----
This morning it happened again, dialog not showing up...so this was not the solution. Actually it got worse now, now every second time the dialog is not showing up. I need to reload the page. This happens on Chrome, I'm trying Firefox.