Sony SCD-C555ES problem with multi-channel

I have this SACD play for about a year and a half and have no problem with it. Recently I bought two SACD and found out both of them have problem in reading the multi-channel mode. The sympton is: it will play and pause and continue to play and pause. The duration of every pause is less than one second and the frequency is random. It only happens in multi-channel mode. It plays fine on 2-channel SACD or redbook CD mode. This also only happens in this two SACD (both are brand new of course) while my other collections of MCH SACD work fine. I called SONY and they suggest power down the machine and unplug power cord, wait for a while and then power it on (I guess the machine is doing some reset sequesnces). It does help a while but problem comes back later. They also suggest I should clean the lens and the last choice is send my machine back for repair.

Any idea?

p.s. I called a local SONY authorized repair shop to see if they repair SACD. The guy on the phone ask "What? a MP3 player? ... What is Super Audio CD?"

Thanks for the help.
Are the troublesome discs Hybrid SACD's. I can't believe that the translucent sandwich is reliable.
Ouch. That last part makes my nervous about my future 555 purchase. The disc itself could be defective...try buying a new one at a different store and see if it plays. Since you stated other multichannel SACDs play, I don't see how it would be the player. New security technology being employed in discs may also be the culprit.
Yes. Both are Hybrid SACD. One is Grove Notes JACINTHA/LUSH LIFE and the other is DGG Holst/The Planets (Gardiner/Philharmonia). Both are relative new release, the DGG was actually just released last month. My other collections of Hybrid SACD, like: Hourglass (James Taylor/SONY) the three Mahler symphonies (Michael Tilson Thomas/SFS labels) are all fine. Somehow I heard the 555 has different laser pickup (?) for CD and SACD. Is Hybride SACD more sensible to read than a straight two channel one? I have returned the Lush Life to Elusive Disc and they are sending a new one to me. The DGG one I have to deal with Tower.

I did clean my lens and no help.

If this is the problem of SONY, I will be much worry in the future if I have to spend thousands of dollar on SACD player with less than 5 years warranty.
All SACD players have different lasers for CD and for SACD...they are different colors. The SACD layer of the sandwich which is the Hybrid SACD is supposed to be transparent at the wavelength of the CD-reading laser, so that the player can look right through the SACD to the CD underneath. I suspect that there will be many problems like yours. I avoid Hybrid discs.