I think i figured it out!
to start with...i have taken the sled out of the dash so many time that the tabs that bend to hold in in place have broken off on the sides....because of this the sled does not sit straight in the dash, but instead is lower in the back than in the front..

thus..when i slide in the empeg i am thinking that the connectos are not making the full contact needed for a good ground (this is because the empeg sits flush against the dash...not flush against the sled)

thus...when i do push against the top of the empeg..it seats flush against the sled...and therefore the connectors seat better against each other..and thus a better ground contact

this morning as i slid the empeg in i made sure i pushed the top of the unit in firmly...whine was almost eliminated...very very faint

what i am going to do is see if i can bolt the sled into the back of the dash so that the opening is flush against the dash to assure a perfect fit

will keep u posted!