It seems like it is worse for you, like it was for me back when I was on Windows 7. There must be some variable, maybe a setting or something.
Latest observations
Win8.1 machine - after 1 week dopus still behaving after many RDP connects, VMMap (paused) very slowly increasing now at 2.5GB (on Win7 it increases much faster)
Win7 machine - Rebooted Friday. Got the stepped increase today (Monday) when logging in locally following a weekend of remote connects/disconnects. It was doing a 1GB -> 2GB increase. I had not noticed any previous increases while logged in remotely.
I managed to capture the dopus.exe thread stack from Process Explorer during the CPU spike/memory increase and after the increase. The after increase stack is quite stable over time. Maybe the differences can shed light on things? leo, jon?
During CPU spike/memory increase
After increase
Interesting, it looks like some kind of bad pointer issue. The kernel is stepping in to catch faults and generate exceptions by the look of it, so perhaps those exceptions could be caught and analyzed.
I hope this can finally be debugged now. Windows 10 is due soon, and presumably there will be a new version of Opus to go with it, so it would be nice to have it resolved in time for an upgrade.
We're not expecting any major changes to Opus for Windows 10. The existing version works fine with the preview builds and we don't expect Windows 10 to be a factor in when we put out Opus 12, which is not planned for any time soon.
Re this issue, I think I may have found something this morning, but I still need to do some more investigation. It's promising, though; I think I have reproduced it once or twice, and have a theory to test now.
That's good news indeed leo, thanks for attending to it.
This may fix the leak, if you want to try the change before the next beta.
Opus 11.13.1 beta needs to be installed first (link in my signature, if needed). Then fully exit Opus (via File / Exit Directory Opus) and, using Explorer or something that isn't Opus, copy the dopus.exe from this zip over your existing one in C:\Program Files\GPSoftware\Directory Opus.
(Test version removed, as the change is now part of 11.13.2 beta.)
Fingers crossed, and maybe we owe you that free upgrade now. 
I'll try to try it out, I'm still running 10 so I need to upgrade first and don't have much time at the moment. Thanks for the quick response.
If anyone deserves credit here, it's beatbox20.
OK I am running test build 5630 now. Fingers crossed.
Happy for mojo-chan to get the free upgrade
I have upgraded my problematic machine and am installing the update now.
Are we right to assume this is fixed now?
The fix that was in the test version is also part of 11.13.2 beta.
Well, it hasn't failed yet, but it can take a while sometimes... Touch wood, fingers crossed it seems okay so far. Out of interest, can you say what it was? I'm just interested to understand how an RDP session could interact with other software in this way.
It was quite obscure. RDP sessions trigger a system-wide env-var change. There are some legacy env-vars dating back to MS-DOS times which have illegal names and confused some code. The two together resulted in a memory leak. The leak was normally tiny (a few bytes), but grew each time it happened, so if you disconnected and reconnected to RDP a lot of times, eventually it grew very large. (Anything else that broadcasted system-wide env-var changes could also trigger it, but it's very rare for things to do that more than once or twice per boot.)
As I said since 2012, it was related to RDP. 
Glad you found it - it was a real bugbear.
Thanks leo, that's interesting. I get it occasionally on another machine that is always the RDP client, rather than the server. It gets put in sleep mode a lot rather than rebooted and it is quite rare, so I suppose it could just be occasional env-var changes building up. It was so rare I was never able to spot any common causes, and it's not related to opening and closing the RDP client. Hopefully you have fixed that now too, but it only happened maybe twice a year.
Btw. - I stopped using RDP from my Mac to my Windows system because of this issue - I'd be happy to let it run for a while if more eyes / testing are useful. For me, the problem occurred pretty much every day or two.
So far so good. I think you may have nailed it leo! Well done. I would say this is provisionally resolved pending further confirmation (and fingers crossed )
Looking back over the threads relating to this issue it seems mojo-chan has contributed the most and fully deserves a free upgrade. Other contributors have been Stormblade, MrC, gmit, onedot3, Drac144, yours truly and maybe others. Thank you all.
I now feel confident in trying to wean myself off TC and on to Directory Opus 
Thanks beatbox20, but I'm not sure bloody minded persistence is necessarily a positive character trait
Well, my trial of Opus 11 is just about to expire and it hasn't failed. I'd say this problem seems to be fixed.
Same here. I've been hammering RDP over the past 2 weeks and dopus hasn't reacted at all. Case closed.
Hope they come through with the upgrade for you mojo-chan.
Er, yes guys, Leo? Any chance of that upgrade, as I can't actually use the fix with V10.