axacropdf EPM error in VB

A bunch of custom applications in my environment use adobe axAcroPDF library to display pdfs. Everything worked well until one day one user requested Adobe Acrobat installed. After installation some applications display an error and will not display PDFs. The error reads "Adobe Acrobat does not support Internet Explorer's Enhanced Protected Mode. (...)" Interestingly EPM is disabled in IE. Moreover, in all C# applications the library works well but in VB applications it doesn't. The only thing that I can see in code is that VB forms not are being instantiated, something that is possible in VB and to me very annoying - when compared with C#. Any ideas?