Forums Bug Reports 7.38 Transparency MDI Bug (Windows 8.1 64)

Vanilla Windows 8.1 Pro 64
No special themes or overlay tools are in use, nVidia drivers are up to date as of time of posting.

mIRC 7.32 upgrading to 7.38 - keeping old ini configuration

Upon loading, any setting for "Desktop Window Transparency" other tha 0% yields very odd visual artefacts, screenshots below. Attempted various combinations of resetting window position, saving window position as default, etc without avail - the only resolution I could find was to set the described option to 0%.

Note, chat windows "behind" the maximised window, even though all windows were previously maximised:
http://www.denyerec.co.uk/stuff/.screencaps/2015-02-12_01-12-40.png


Note the blank userlist, which would appear when clicked on:
http://stuff.denyerec.co.uk/.screencaps/2015-02-12_01-25-33.png

Note the black/broken "Restore" sized window titlebar:
http://denyerec.co.uk/stuff/.screencaps/2015-02-12_10-40-29.png

Note black "restore" sized title bar in backgroun, also nickname list remains black until clicked on:
http://denyerec.co.uk/stuff/.screencaps/2015-02-12_10-41-51.png

Reproduction steps:
- Set "Desktop Window Transparency" to any value other than 0%
- Sit back and enjoy the craziness

I do not / did not have any windows set to desktop mode, all chat windows are "normal" and contained within the mIRC parent window.

Thanks for your bug report. mIRC only sets the transparency setting for a Window - the actual display of transparency is handled entirely by Windows and/or the graphics driver. It looks like Windows 8 has support for transparency in MDI windows - previous versions of Windows did not. This could be a Windows 8 and/or graphics driver bug or a new feature. mIRC was applying the transparency setting to Windows regardless of whether they were MDI or desktop, as it never made a difference to MDI windows before. I will make a change to the next version of mIRC so that the transparency setting is only applied to desktop windows.

The bug only seemed to present itself after he upgraded from 7.32. Was there a change of behavior or API since then?