I have a very similar issue, and I have 32bit XP SP3 with all patches. AcroRd32 is 11.0.07. The error in my case is:
The exception unknown software exception (0xc0000409) occurred in the application at location 0x603122f3
The behavior in my case is also slightly different - after clicking OK on the error dialog, I still cannot open the PDF I selected. So far this has been true for every PDF I have attempted to open. I also ran the Repair option on Adobe Reader XI and that made no difference (and I did reboot after repairing).
I have tried PDFs from a variety of sources: created on my system by products such as PrimoPDF and CutePDF and created elsewhere (online) by third parties (such as product manuals). All give exactly the same error, which leads me to believe it's an application error.
This is new behavior since the last update.