‘Open’ and ‘Save’ windows defaulting to screen top left

I'm trying to get to the bottom of an issue that seems to be affecting all the supplied themes except the default Windows 8 theme (I'm using the current version of WindowBlinds on Windows 8.0 Pro).

Here’s an example of what I mean:

If I open up a common desktop app (e.g. Photoshop CC 2014) and press Ctrl+O to bring up the ‘Open’ file browser window, the window will open top left of screen just under the title bar. If I then move the window to the middle of the screen and resize it, the normal behaviour of Windows is to remember the size and position of this window and retain it next time it gets opened.

However, having tried this several times, I can only get this to happen if I switch to the default Windows 8 theme. If I apply any of the other themes (and I've tried a few downloaded themes) only the size of the window will be retained, but the position will always default to screen top left.

As I say, this only happens with windows opened by an application (and only with those that use a system API window for load/save instead of generating their own dialogue, which is most of them), if I open a file explorer window on the desktop, previous size and position will always be retained.

Might seem like a trivial issue but after years of working with centred windows, it’s not just annoying, but actually affects my workflow (used WindowBlinds on Windows 7 for years without encountering this issue).

Any insight on this appreciated.