C:\Program Files(x86)\Cakewalk\Vstplugins\ should be the path for 32 bit VST's

It may be having a problem with the 32bit and 64bit VSTs being directed to the same place(?) - they may have the same name.
(or left over Registry entries that it hasn't cleared properly).
 
I suggest you should maintain your own and separate VST2 locations (for third party VSTs).
See - http://steamcommunity.com/sharedfiles/filedetails/?id=299042505
(Steam paths replaced with regular Program Files paths).
 
Create the top level directories, for each of the 32/64bit versions, via Windows File Explorer prior to definition to the installer/install.
 
I agree with Mudgel - your 'wall of text' posts are hard to read ... nearly to the point of losing my interest.

Hello Everybody! I'm asking Addictive Drums 2 (XLN) if they have a fully functional 64 bit Vst version...
 

Are you asking them at the XLN Audio Site or here? ... because I'm not aware of an XLN representative on this forum.
(Cakewalk simply provides a License Key. The software is FULL and independently supported by XLN Audio. Sure - they likely have direct lines of communication, but I'm not aware of any requirement to such escalation ... yet).
 
However, the answer is "yes", as far as I'm aware. It's only VST2 (not VST3) but appears fully functional to me.
I've checked, as I eluded before, and sure enough the 32bit and 64bit VSTs are both called "Addictive Drums 2.dll" so the MUST be installed to different locations.
 
I suggest you:
1a. - create two VST2 Plugin directories say:
C:\VST_Plugins_32
C:\VST_Plugins_64
1b. - Define these appropriately to the Sonar VST Scan Path list. On 64bit you can add both - 64bit will take precedence on double-ups otherwise BitBridge will usually handle 32bit to 64bit conversion.
2a. Create a directory in each - XLNAudio
2b. Put theses directories appropriately into the XLN Online Installer "Advanced" tab.
 
... and install
 
... and start / (auto)scan from Sonar
 
(Standalone will be installed too).
 
Use these locations for future third party VST2 installs (in appropriatlely created subdirectories). They will be picked up by Sonar because you've already defined the 'root' locations to the Sonar VST scan paths.

I have the same problem, but on a new computer. 
During install, AD2 reports the 32- and 64-bit paths are correct.
I created two new dirs for these, pointed the installer to them, and the install proceeded.
Started Sonar Prof, and got the error messages as above, re wrong binary location.
Updated Sonar via menu Edit > Prefs > File locations > CST > Add...
AOK now, I think.