Why does PDF in IE window only show up when connected via DameWare?

Question

Java

There is a certain system for internal use, client parts work actively using Java. The system is capricious: it requires a strictly defined version of Java, as a browser only IE is not higher than the eighth, it often bugs out of the blue.
In the system, you can view the files attached to the elements, including PDFs: by clicking, a window opens in which the standard IE add-in for viewing PDF is launched. In some cases, the file is simply opened.
One user has Foxit PDF Reader set as the default PDF viewer and attachments are opened with it. But when viewing a special type of document, an IE window opens with the Acrobat Reader or Adobe Acrobat add-on running, both are installed on the computer. Apparently, the system is hardcoded to open these documents only with Adobe software.
The problem is that the add-in starts, but the document is not displayed - a blank gray background! But as soon as you connect via DameWare Remote Connect and try to open the document again, it miraculously appears!
Colleagues, I will be grateful for the thoughts, what's the catch. In theory, "damovara" and this self-written system are not connected at all ...
The user and the connecting Win 7 x64 with the latest updates, Kaspersky, computers in the AD domain, DameWare version 9, Windows NT Challenge / Response authentication type.