Good questions. All I can say is that I had the problems since I added the player in my system. After the correction of the PUC everything is working perfect :-)

Thanks.  It is a very strange problem. I can use the player with single clicks, turns on and off at source change just as it should, all works fine. Then when I try to turn it on later it requires double clicks. Might try changing to a different HDMI output and see if that has any effect. 

Went into the puc menu and changed from Sony BDP-S300 to Sony BDP-XXX. Double click problem occurred with that setting as well. Tried puc for Sony DVD and nothing worked. Changed it back to Sony BDP-S300 and all is working again for now.....no double click problem.

Very strange and frustrating.

Double click problem returned again. I have now set the menu on the BV7 to manual and use  GO 9 to turn the player on and off rather than having it do so at source change automatically. So far no return of the double click problem. 

edit     after hours of functioning properly through multiple on/off cycles the double click problem resurfaced.

This is getting even more perplexing. I pulled out our old Sony BDP-S300 and set it up  next to the 550. When the double click problem occurs on the 550, if I remove the ir emitter from the 550 and put on the 300, the 300 works fine, no double click problem. So, the conclusion...the problem is with the 550......but......if I then replace the ir emitter on the 550 (no setting changes at all)  the 550 suddenly works again...double click problem is gone!

Have you checked if there is a firmware update available for the 550? (The 350 has an Ethernet port for this purpose, I presume the 550 has as well)

There is a firmware update available. None of the listed improvements have anything to do with the remote, but I do need to try that. Might be something that would fix the problem.

I am increasingly becoming convinced it is something in the BV7. When the problem occurs, if I leave the BV7 on, unplug and reconnect the player, the problem is still there. If I leave the player running and unplug the BV7 and reconnect it the problem is gone. So my conclusion is that whatever the problem is disconnecting the power from the BV7 fixes it, temporarily. 

I have also noticed that when it stops working after an hour of use, it is with heavy use, pressing buttons frequently. Last night it was working and I just turned it off. It still works this morning. So, my conclusion is that it is not time related, but use related.

I am wondering if perhaps using the Beo 4 with two button commands for certain functions  (GO ARROW for instance) is maybe causing the problem if I do not push the two buttons at just the right speed and then the problem occurs where I must press GO ARROW GO ARROW for instance. Have ordered a Beo 5 and am hoping with it perhaps the problem will not be present. (Did not order the Beo 5 just because of this problem)

Here is a strange new twist on the double click problem. I now am using a Beo 5 and have the puc assigned to Sony BDP-XXX. It works with no problems. However, periodically the double click problem will return. It seems to return when sources are changed. i.e. if system is in standby, and is turned on to Blu-Ray from there, and then when done with the Blu-Ray the system is turned off, the double click problem does not occur and all works fine. Occasionally, however, if the system is switched directly from Blu-Ray to another source, or from another source to Blu-Ray the double click problem returns. 

Now, here is the weird part.

When the system is functioning correctly with no double click problem and is turned off, the red standby light comes on and remains on, as it should.

When the double click problem is present, and the system is turned off, the red standby light comes on....but.......after one minute the red stand by light blinks 5 times and then again remains on as it should. If the system is turned back on before the 1 minute/5 blinks the double click problem is still present. If it is not turned back on until after the 1 minute/5 blinks the double click problem is gone.