For some time now, with 2.6, I have had issues with using Spark via Windows Remote Desktop. The Spark window just does not redraw correctly and so the application is rendered useless. Have previously reverted to 2.5.8, but now that 2.6 is nearing release, I tried the latest build and the problem persists.
The login screen is ok. but the menu drop downs in the main window, dont draw correctly. Context menus seem ok, as does the roster list.
Can you specify which themes exactly cause the problems? I’m now working via RDC from XP to Win 7 x64 and it works fine with BusinessSteel Blue skin and Windows skin.
Also Spark skinning support is a subject to change in the future. There are plans to drop support for many unpolished skins and leave just one polished. Also Substance skinning api is not developed or supported anymore, so probably we will have to switch to something else.