I would say, dont use any vst3 until the new patch, if you use the vst2 versión from waves it shouldn´t be any problem.
 
 
 
 

Is this problem only with Waves vst2 AND waves vst3 effects in the same project or is it more general to include waves vst3 and any other manufactorers vst2s?  Sorry to ask, but wanted to find out if it happens when Waves vsts3 are mixed with other vst 2s.
 
I know it will be fixed, just curious.

Well...anyway you cant use waves vst3 because they just loose their settings once you save and reopen the Project.
 
I dont know if happens with all vst3 plugs...I would suggest to stay away from vst3 until the patch.

The bug has been fixed and seems to affect only some VST3 plugins which is probably why it wasn't noticed earlier (it broke very recently). The fix should be available later this week if all goes well with testing. The settings are saved OK while you are in the session but when you reload it some parameters get reset to defaults. 

 worked on a mix all night yesterday to find all my settings gone.  Now I find out about x3b addressing this issue!  I just bought x3 and the download was for x3a.  I hope when I install the patch it remembers my settings!!!!

I know this is an old thread, but I am experiencing this issues now. I am using the latest SPLAT and Waves builds.
Noticed with Desser, Maxvolume, C4, Maxxbass.
 
Not just Waves either, some Fabfilter plugs as well (for sure the Pro-DS off the top of my head)
 
It MAY have something to do with the Upsample settings?

It also seems to be resetting the Drum Replacer settings as well

Bump, this is still an issue

djtrailmixxx
Bump, this is still an issue

I'm glad someone is bumping this. I am having huge problems with Waves plugins having their controls reset. It's mainly the SSL-Channel and Q10. I'm really frustrated about it because it's completely destroyed hours of work getting EQ sounding just right. I load the project later and things sound awful. Open the Waves plugins to find many of my EQ settings have been hosed. 
 
This plugin resetting business is quite possibly one of the most frustrating things I have found in Sonar. It's been happening to me for as long as I've used the program. It used to be Native Instruments plugins as well, but they seemed to have fixed that issue. And at one time I was even opening projects to find all instances of the Quadcurve EQ in the ProChannel messed up with crazy EQ boosts or cuts of 16dB in the same frequencies. If you can't rely on your mix settings being saved with the project then the DAW is functionally useless. We really need to get to the bottom of this. I would even advise Waves users who are thinking of buying Sonar to hold off until it's fixed. Let's start reporting this issue again. 

I am not convinced this applies only to waves either. It vseems to be a general VST issue.  I have had several projects where synth patches have been lost, particularly after archiving then restoring tracks. 
 
Its a tricky one though. I am yet to reproduce it consistantly.