hi, jksuperstar! it seems that that is particularly loss of part of sinewave, the sync is internal.
gruebleengourd, i don't think that it's a problem of Scope 5.1, as far as I remember Scope always had a 'sensitive' driver, just on the older computers it was less shit going on concurrently, so if you calm everything down and leave Scope more or less alone, it works fine.
I have tried every combination of suggested 'scope tweaks' like disabling, degrading, crippling something, like less cores, no speedstep, less devices but in the end i observed that in my system it doesn't change anything (but degrade performance for other tasks).
I've been able to get 10 hours of glitchless recordings with 4ms buffer, but I had to tune daw's process priority and make sure no p2p or browsers are running along. windows somehow doesn't care too much about priorities, you can still choke higher priority processes with lower priority power hungry tasks. I have a lot of hardware in this system, but it all plays along well. Although Lynx shares IRQ with SCSI, it's quite more click-impermeable even without priority tweaks. Somehow I think that Scope driver revision could make things better. IRQ conflict is when thing doesn't work at all, but in our clicky cases it's just device getting attention too late. Why Lynx with same buffer is happy and Scope is not? By the way, when I don't have clicks, I don't have them at any buffer setting. When I do, even largest doesn't help. What I also noticed, that even software doesn't know about those clicks. DAWs have an indicator of lost buffers. For other cards, if they click, the counter turns red and indicate lost buffers. For scope, it does only sometimes, only with 'specific' clicks which are rare. My theory is that this buffer loss occurs somewhere aside ASIO, how to say. Before it, maybe. As I understand, Scope has to run it's own OS and that OS presents ASIO ports to applications, and you can draw as many ASIO channels as you wish. Within that Scope OS everything works fine, so that's why VDAT never drops out. it's between Scope and ASIO, between Scope and wave driver it presents to a system, that's the place where it doesn't get enough priority and something nasty happens. Developers should see this post and comment on it 

And by the way, I have no problems with VDAT under x64. Just make sure there's no April ..355 update installed.
IRQ 0	System timer	OK
IRQ 1	Standard PS/2 Keyboard	OK
IRQ 3	Communications Port (COM2)	OK
IRQ 4	Communications Port (COM1)	OK
IRQ 5	Printer Port (LPT1)	OK
IRQ 8	System CMOS/real time clock	OK
IRQ 10	Intel(R) 8 Series/C220 Series  SMBus Controller - 8C22	OK
IRQ 10	Intel(R) 8 Series/C220 Series  Thermal - 8C24	OK
IRQ 13	Numeric data processor	OK
IRQ 17	PCI standard PCI Express to PCI/PCI-X Bridge	OK
IRQ 17	Texas Instruments 1394 OHCI Compliant Host Controller	OK
IRQ 20	PCI standard PCI Express to PCI/PCI-X Bridge	OK
IRQ 20	Adaptec SCSI Card 39320A - Ultra320 SCSI	OK
IRQ 21	Lynx AES16	OK
IRQ 21	Adaptec SCSI Card 39320A - Ultra320 SCSI	OK
IRQ 21	Intel(R) 8 Series/C220 Series  USB EHCI #2 - 8C2D	OK
IRQ 21	Intel(R) 8 Series/C220 Series  USB EHCI #1 - 8C26	OK
IRQ 21	Intel(R) Active Management Technology - SOL (COM3)	OK
IRQ 22	PowerCore/Classic	OK
IRQ 23	Sonic Core Scope	OK
IRQ 4294967281	Intel(R) USB 3.0 eXtensible Host Controller - 0100 (Microsoft)	OK
IRQ 4294967282	Intel(R) HD Graphics 4600	OK
IRQ 4294967283	Intel(R) Management Engine Interface 	OK
IRQ 4294967284	Intel(R) Ethernet Connection I217-LM	OK
IRQ 4294967285	Intel(R) I210 Gigabit Network Connection	OK
IRQ 4294967286	Intel(R) I210 Gigabit Network Connection	OK
IRQ 4294967287	Intel(R) I210 Gigabit Network Connection	OK
IRQ 4294967288	Intel(R) I210 Gigabit Network Connection	OK
IRQ 4294967289	Intel(R) I210 Gigabit Network Connection	OK
IRQ 4294967290	Intel(R) I210 Gigabit Network Connection	OK
IRQ 4294967291	Intel(R) 8 Series/C220 Series  PCI Express Root Port #3 - 8C14	OK
IRQ 4294967292	Intel(R) 8 Series/C220 Series  PCI Express Root Port #2 - 8C12	OK
IRQ 4294967293	Intel(R) 8 Series/C220 Series  PCI Express Root Port #1 - 8C10	OK
IRQ 4294967294	Intel(R) Desktop/Workstation/Server Express Chipset SATA RAID Controller	OK
What software are you using with ASIO? Some are more successful than others.