I had a problem up until recently involving the mixing of OpenGL draw calls and SFML draw calls.
I'm focusing on using OpenGL itself and simply having SFML handle input, OpenGL contexts, Mutex, and a few simple sprites.
While implementing my more advanced model loading/displaying, some sprites within the program stopped drawing (pause menu sprites for the game), it was nothing major and I ignored it until my next bug sweep.
Anyway, I found no answer on the internet or these forums from my searching, but I eventually worked it out.
I am unsure if its a bug, not a feature yet, or something that push/resetGLStates will not handle, but it did not reset the GL_VERTEX_BUFFER I was using for my models. It was in the end my fault, as I should have been resetting the buffer after using it, but I'm an idiot sometimes.
I thought I'd share the results here in case someone else has the same issue, or if the development team would consider implementing resetting the vertex buffer when calling push/resetGLStates because it interferes with SFML draw calls if a buffer is currently set.