I have a mixed .NET application (managed and unmanaged code bridged by C++/CLI wrappers) which uses unmanaged Direct3D9 9.0c to do rendering inside a control which is wrapped inside a C++/CLI class which extends System.WIndows.Forns.UserControl.
Everything has been working fine for years now, but I recently put another instance of this Direct3D9 control inside a new Windows Form. That is, I have two concurrent instances of the control. I had done that before and it worked, but now I have issues. Perhaps the problem was always there, but because it's related to a race condition, it started happening now...
Ok, the details: When I try to render an image over a texture on the new instance of the control, sometimes it works, sometimes it doesn't. And when it doesn't, nothing is rendered, and from that point onwards, all Present calls fail (I log those failures). If I close the form and open it again, it might work or not. Nasty.
If I use DXGetErrorString and DXGetErrorDescription, all I get is something like:
EFAILED Undetermined error
Not really helpful... To make matters worse, I can't reproduce the issue in my development environment; I only see it in a production box.
As far as I know, the main reason Present fails like this is a Lost Device. But I implemented the usual scheme to handle that (I can post the code if necessary), and it seems like the device is not being lost... What else can I try?