Rega DAC problems

I'm having trouble getting my Rega DAC to lock on to a 24/192 feed from my Oppo 105 disk player.
I'm using Toslink connector and playing a Blu-Ray version of: Yes - Close to the Edge.
The DAC is showing 44.1-48K.
I've checked the settings on the Oppo and they look proper. Pressing the info button displays 24/192 as the sampling rate.
I tried asking Rega for help but Agon email address came back invalid.
What am I doing wrong?
This is from the Rega DAC manual:

The optical system used for optical inputs 1&2 is nearing its
maximum at 192K. If you experience difficulties try the
following: Use a higher quality or shorter lead. When using
3.5mm jack outputs commonly found on computers and sound
cards etc. Try and use a mini Toslink optical 3.5mm
jack connector lead and avoid using a 3.5mm to full size
adaptor with a standard full size Toslink lead.
"When all else fails, consult the manual" -words of wisdom.

I'm using a glass fiber Toslink and should fall under the "higher quality" category. OTOH, it is three meters long.

I'll wait for a rainy day (long wait in 'Vegas) and experiment with shorter Toslink cable, RCA, etc.

I'd sure feel cheated if I can't get this to work.

Thanks for your responses.
No, not yet. The Oppo is too far away from the Rega for my vintage 1-meter Audioquest digital cable.
I may have some time over Thanksgiving to play with it.
You would think that if the Toslink can't support 24/192 that it (the Rega) would downshift to 24/96 or 16/96?
Well, I tried moving the Oppo closer to the Rega and hooked up with an RCA connector.
I think I'm hearing better sound with the Yes BluRay (original stereo mixes @ 24/192, 2013 mixes @ 24/96)
but the Rega LED always shows 16/44.
I've checked all Oppo audio settings and don't think this is the problem.
This is so frustrating.

The higher sampling rates sound smoother and require a volume boost (usually play @ volume "60" BluRay required "75" for equal loudness.

Mr. MoFi: I can't find the passage about Toslink in my manual.
Does Rega think they've worked this out by now?
FYI: I purchased my DAC in the last 6 months.

If anyone has a Rega that shows a 96 or 192 data lock,
please drop me a note. -Thanks
I came across this post recently and experienced the same things with Blu Ray Audio Discs running into my Rega DAC. I had it explained to me that it is a copyright protection issue with Blu Ray and will only output CD quality through the digital outs (coax and optical).
tune_man: Thanks. I guess it was too much trouble for Rega to note this somewhere. Looking forward to MQA. 
My Blu Ray Player is connected by coax to the Rega DAC and shows 44.1-48k with Blu Ray Audio as I stated but Redbook CD's played on that player show 88.2-96k and I know they are 44.1. I think the Player is upsampling as I have a Logitech Squeezebox Touch and Denon universal Player connected to the DAC with Coax and Toslink and my ripped CD's (FLAC) and Redbook CD's show 44.1 when played on those devices. My Hi-Res files from HD Tracks and Qobuz show 88.2-96k as they should when played through the DAC from my Squeezebox.
I will try and find out more and report any findings.
Thanks for your interest and effort. I've always felt ripped-off that I couldn't playback hi-res from my Oppo. It would be interesting to know if 192/24 downloads would lock-on to player.
I can't try that out as my Squeezebox Touch only supports 24/96 and below and downsamples 24/192 to 24/96.
I hear you though as I picked up the Rega DAC for all it's inputs and Blu Ray Audio, SACD and DVD-Audio won't benefit from these connections to the DAC. Very frustrating indeed! 

@craoul79 Yes! When I try playing anything with 88.2kHz sample frequency, it comes out horribly distorted. And it's not a cable capacity problem, because it works fine if I upsample to 96kHz. I tried with both 16- and 24-bit width, and 88.2kHz is a problem in both.

Did you ever find out anything more about this?

The Rega DAC is long-gone. I think the root cause being my DAC was a Mark-I.

I think Rega fixed the problem in the Mark-2.

The BluRay copy protection probably still valid. I love the sound and convenience of digital but the environment is far too complicated and confusing. I haven't even considered streaming (P.S. I was a Mainframe programmer for 20 years).