I'm experiencing the same issue and wondered if you have any news re this problem or have found some workaround ?
I've performed tests on all verions of Safari 5.1.x including the latest 5.1.4 and unfortunately the bug still exists.
Thanks in advance for your consideration and any help!
I am sorry to say that I did not notice any progress regarding this issue. And no, I don´t have a workaround.
I think it´s a shame that Adobe and Apple were not able to fix this serious issue till now.
It seems that the Adobe plugin is not compatible anymore and I don´t see any efforts from Adobe to fix this.
It is really annoying and hard to understand.
Does anybody have a solution for the same? PDF form submit doesn't work in 5.1.7 too.
For what it's worth, I can't get submit to do anything on any browser, Mac or PC.