"I've added digital channels to my Philips 3575 with the Manual Channel Preset menu."
Well I just did a test and I cannot add digital channels to my 3575.
What I did was this: Manually deleted ch17 digital, which included 17.1-17.5
I also deleted ch23 digital, which included 23.1 & 23.2
I then tried typing in 17.1 and only got a blue screen. Then I went into DTV channel setup and typed 17 and checked the ADD box. It only went to a blue screen. I tried 23, with the same results.
There was no way that I could add the digital channels. Then I tried a channel scan, and it found all the 17's along with the 23's.
So I stand by my initial comment that digital channels cannot be manually added, unless by a rescan.
Not sure why you are seeing different, but I believe you have cable, while only have OTA. Maybe that's why?
On a side note, I have Insignia LCD TV, that seems to do a automatic digital channel scan, all by itself. All the sudden I will have an extra digital channel in the scan list. But if I delete the channel, I cannot add it back, unless I do a channel rescan. I really like that feature, my Vizio and Panny LCD do not do this auto rescan, so I would never know there were new digital channels out there.
I got it. If I add the real channel 35(not the virtual 11.1) I can add the channel. Then it also adds all the . channels.
I'm currently testing my Panny for the timer bug, so I dont want to power it up to check it out right now, but I will try later this eve. to see if I can add the real channel vs the virtual ones on it.