See Gary's post 9. It should fix the problem.

You have two options first one is include the path in the scan or copy and past the dll to the right path. 

Thank you Gary & John!  Odd, I stuck every Spectrasonics and Steinberg folder in the plugin mgr. last night, rescanned, shut down X2, reopened it and no change. 
 
Got home today loaded X2, it re-scanned and now I'm 32 bit free!   Am happy.
 
Oh, and I think I've finally reinstalled everthing.  Phew.
 
 For Spectrasonics devotees who haven't seen this from another forum, Mr. Persing posts: http://www.northernsounds.com/forum/showthread.php/103533-Is-Spectrasonics-out-of-Business?p=721307&viewfull=1#post721307

I finally managed to get Trillian to appear as 64-bit only, but I've been wrestling so much with VSTi's (especially Battery 3) over the past couple of days that I can't say exactly what fixed it.  

I did a lot of VST re-scanning and changing file security permissions, also running X2 as Administrator as well as under my user account.  After a lot of mucking about (and a reboot after X2 went completely bananas), suddenly my plugins were all there.

I understand, and am glad all is well. 

Still struggling with this.  I have 3 files called StylusRMX.dll ---------- how do I tell which is the 64 bit one?  None of the Spectrasonics .dll files have "64" in the file name.

Also, it appears to me that Stylus RMX is working fine - even though it says its 32 bit.  What actually is the difference - will 64 bit sound better or ...?

ultrabra, 64 bit is a faster data transfer rate It affects performance not sound.  Is the UI for RMX showing it's 64 bit? (click on the "floppy disk" icon at the bottom right it should say at the bottom).  Make sure it's the latest version (1.9.6e)because my install discs are so old that they are 32 bit.

If all the folders where your RMX.dlls  are located have been scanned by Sonar, go back into the plugin manager and click options.  Make sure all files associated with Spectrasonics/Steinberg are in the folders that show up.  If not, add them.

Then click on re-scan existing. Then close Sonar, reboot and open it up again.  That's what worked for me.

I still don't know understand why it worked.  There were no .dll files in any of the Spectrasonics folders (they were in Cakewalk/Vsts).   Good luck.

Hei Declan - thanks for the reply.    When I "Insert Soft Synth" inside Sonar X2  its saying"StylusRMX (32-bit)".   But, when I checked from the Utilities icon like you suggested, there it says, on the bottom line "Stylus RMX, 1.9.6e 64 bit" - so that suggests that actually I DO have 64 bit version working - so no idea why it displays "32 bit" in the soft synth menu ... ?!

In my case I think I may have screwed up by not running all the updates before scanning in X2 - I'm not sure.  I wouldn't worry about having 3 RMX .dlls (but I didn't) but tell me where those .dll files are.
 
Make sure you're rescanning "all existing plugins" and not just scanning "all plugins" or vsts, because that solved my problem after I threw every seemingly empty Spectrasonics/Steinberg folder  in the plugin manager then rescanned, shutdown X2 and rebooted.
 
Don't get as frustrated as I did :-).
 
 
 
 
 
 

Hei Declan - sure I posted this yesterday - must still be getting used to the new forum layout :-)
 
...
I have 2 x stylusrmx.dll files (identical size and date) in the Steinberg and Spectrasonics folder --- these are old, from 2005.   Most recent, May 2011, is in my normal cakewalk folder where all my VSTs are.
I could rescan to include the Steinberg and Spectrasonics folders, but I'm fairly sure that these folders include only old drivers.    The newest driver does show the Stylus RMX, 1.9.6e 64 bit (showen as you said by pressing the Utilisites icon in bottom right) ... only issue is it displays 32 bit in the insert synth menu ... its a mystery why but seems to be working solidly anyhow ...
 
Thanks also for the Spectrasonics link above - nice to hear there are some new things coming "sometime soon" ...