According to the bug fix list the jump to zero issue should have been fixed. Unfortunately I cannot check this because Version 1.70 crashes Cubase (versions 8.5.15, 8.040 and 7.50). The plugin is then placed in the Cubase VST blacklist.
I went back to ver. 1.61 and Cubase excepts this one.

OS: Win7 x64, PC: Intel i7, 12Mb RAM, DAW: Cubase 8.5.15 x64

I did make a screen capture and posted it to my facebook page.
[img]https://www.facebook.com/media/set/?set=...&uploaded=2[/img]

Same here. It hit a crash on Cubase 8.0.40 during the initial plugin scan, and 608 MD gets listed in the black list. Downgraded to 1.6.1 and Cubase runs fine.
Actually I've reported the issue to PSP folks via email and they are looking at this issue as we speak. Unfortunately AFAIK they are not able to replicate the issue locally so far. I'm adding some more info than usual below, hopefully helps to repro.

Cubase 8.0.40 x64 / Win7 x64 / Core i7 3770K / ASUS Z77 MB / 32GB DDR3 / UR44
I have installed x64 VST only; but to a different folder than the default.
This Win7 has UAC completely turned off. Logged on as the admin.
Using an old NVidia low end graphic card
(in an effort to workaround the painful Cubase 8.0.20 paint-perf regression - the card didn't solve that but didn't bother removing from the box. The issue was fixed in 8.0.40, BTW).

Meanwhile, if the RTZ issue is still suffering, there's a workaround:

http://www.pspaudioware.net/forum/ubbthreads.php?ubb=showflat&Number=9301#Post9301

Last but not least, I appreciate PSP's giving free upgrade to the existing users.

Hi Guys,

Please contact us at support@pspaudioware.com

Warm regards
Antoni