Audio glitches with Fast Track Ultra on Windows 10 after updating Windows 10

[GregS]

I'm experiencing audio clicks & pops when playing real time VSTi's using the Fast Track Ultra. I think this problem started immediately after the most recent Windows 10 update. (which I think was a big update). If I switch to ASIO4ALL using the integrated audio interface, the problem goes away. I have tried stopping as many background processes as I can. Just in case it's relevant, I notice that in the M-Audio control panel, when I click the "Setup" button at the top, the pop-up window does not display immediately - it kind of "unfolds" in a gradual and jerky fashion. It may just be an intended transition effect, but if it's not, this could be a sign of a problem, I think.
Tried two instruments so far: Kontakt 5, and Pianoteq 5 (both in standalone mode)
Environment:
I normally run at 44.1kHz and a 128 sample ASIO buffer. I'm not sure yet whether increasing the buffer size completely eliminates the problem, but I think it does help.
Windows 10-X64 Pro (last updated 23-Dec-15)
Fast Track Ultra driver version 6.1.10, firmware 1.5.1
Dell M4500 laptop, Core i5 M540 @2.53GHz, 4GB (this laptop is rather old)