Hum and hiss with Rives Parc

I have recently installed a Rives Parc into my system. It has introduced an annoying hum and an audible hiss. I have isolated the earth temporarily and eliminated the possibility of a groung loop. I have tried a different power cord (Eichmann Express) to no avail. Has anybody else had a similar issue with these units? If so any help would be appreciated. I am using a Chang Lightspeed power conditioner.
??? The PARC was one of the most dead silent components I've ever used. Have you tried bypassing the power conditioner and just plugging it into the wall?
Yeah - tried that. No better. Tried a different power cord - no better. I'll put it into a friends system and see if it is still the same. Might be a faulty unit which could be a problem because I am in New Zealand and purchased it from a dealer in Singapore. Any other suggestions much appreciated.
contact Rives----great people there.
Something must be wrong with the unit. Mine is silent.

Thanks guys

I have dropped Rives an email. Should be able to get it sorted. It makes a wonderful difference to the bass. After years of messing around with various room treatments, I finally bit the bullet.
We did receive an e-mail yesterday and responded to it yesterday. Some of the suggestions you've already tried. Others have to do with other equipment in the system that we have found issues with. Because the answer does speak about some specific brands that have issues we won't post the information in a public forum. Lastly, it is possible there is a problem with the unit, but we'ld like to be sure it's a unit issue before you send it back. We have had so few repairs I find it very unlikely that's the case.

Please let us know what the results are and we will work with you from there.
Thanks for your reply which I received. I really appreciate it when a manufacturer makes the time to offer advice. I would like to add that apart from this issue the unit has sorted out my bass problems instantly without doing anything to the midrange or higher frequencies. Sounds fantastic.

I will try a few of the ideas you suggested. I'll let you know the outcome by email.