The disappearing-plugs problem can be cured by checking "Use VST prefix" on the first screen of VSTConfig. This organises your VST plugs in to a sub-menu of the DX menu...

What do the "error popups" say exactly?

Hi Angus.
I have several problems with all versions of VST ADAPTER (i have the latest 3.3.2 at the moment) and the Ultrafunk sonitus FX 2.0b plug-ins.
If u try to install both versions (direct x and vst) when the adapters scans the vst plugs some pop up errors appear.
After that opening SONAR 2 XL (but with SONAR 1.3.1 is the same) the DX version of the Ultrafunk plugs are completely disappeared and only some plugs (3 or 2 of the total of 7 plugs) of the VST version are available.
If u try to use SONAR after a Full Reset of the ADAPTER (with no VST/VSTi entries) the DX version of The ULtrafunk plug-ins are still available (but with a DX plug-in less (FX WHAWHA).
Is a very strange way to handle a plug-in!
In the past i have a lot of problems with the sonitus and i use to work deleting all the VST version exluding the WhaWha (i like it and i need the automation available with VST version only...).
Using only the whawha as VST the other Direct X works very well in the past but now i must delete the VST WhaWha and also i must remove the Ultrafunk FX Surround from the DX entries(with REGEDIT)or the DX version of the WhaWha disappears like the VST!!!!
I can't understand that...Do u have an answer?
See ya.

Sorry but still don't work...