After unloading ARP2600 V 2.0 and then loading any different VST-Instruments or PlugIns, they appear with an empty gray window without any controls. This should be a known problem, because it exists since a very long time. Almost every Arturia-Synth had this problem and it was fixed in many of them. The Prophet V 1.2.1 has also the same bug.
I'm working with Cubase 5.1 on Windows XP
