[Zuman]

I'd appreciate some help from someone who understands these things better than I do (probably everyone here...).
My turntable is a heavily-modified Rega P1. It has Lim top and bottom plinth braces, a Groovetracer Reference subplatter, a glass platter, an Achromat, a Little Belter belt, an RB330 tonearm, and a Clearaudio Virtuoso Wood cartridge. It sits on an Isoacoustics platform on a Solidsteel rack.
I have a relatively new copy of the UHQR pressing of Kind of Blue that I've listened to about two dozen times. On Side 1 of the record, the stylus has begun to "stick" and repeats ad infinitum about two-thirds of the way through the record. I handle it carefully, and the playing surface has never been scratched that I am aware of (and I can't see anything with the naked eye), and the table has never been knocked or jarred. It did not always happen, and it does not occur on the other side of the record.
I THINK I have tracking and antiskate set properly, but I have a vague suspicion that an adjustment might fix things. I do use a carbon antistatic brush that I'm careful with.
Any suggestions? I'd be very grateful for advice!

[Stercom]

Check your Vertical Tracking Force (VTF). Every cartridge/arm has a recommended VTF. If it is set too lightly it can cause skips. The anti-skate is also a possibility but you will usually know that immediately because the cartridge will "skate" across the record.  Here are a couple of videos.

https://www.youtube.com/watch?v=86_2QIWs7jA
https://www.youtube.com/watch?v=LYAbWTt3Akg

[S Clark]

The tracking force for that cartridge is 2-2.5g.  Set it to 2.5 and see if it solves the problem.  Use an electronic scale.  If you don't have one, spend $15 and get one. 

[Zuman]

Thanks. I measured the tracking force at 1.9g and increased it to 2.5g. That actually cleaned some junk out of the groove and behold! all is good now.
I appreciate the guidance.

[S Clark]

Glad your initial problem is solved.   That's a nice lp.  If the stylus is cleaning dirt out of the groove, that's not a good thing.  There are lots of cleaning kits out there that all work- some much better than others.  But even a bristle hair paint brush, some soapy water, and microfiber towels to dry are better than a high quality record with so much crap in the grooves that it builds up on the stylus. 
There are 13 pages on cleaning here....  https://www.audiocircle.com/index.php?topic=3377.0

[Zuman]

Glad your initial problem is solved.   That's a nice lp.  If the stylus is cleaning dirt out of the groove, that's not a good thing.  There are lots of cleaning kits out there that all work- some much better than others.  But even a bristle hair paint brush, some soapy water, and microfiber towels to dry are better than a high quality record with so much crap in the grooves that it builds up on the stylus. 
There are 13 pages on cleaning here....  https://www.audiocircle.com/index.php?topic=3377.0

Yep. I use the low-tech but effective Spin-Clean, but I haven't cleaned the LP in question yet. I guess it's time already!

[S Clark]

The Spin Clean seems to be a very effective low cost cleaner. 

[davidc1]

Yep. I use the low-tech but effective Spin-Clean, but I haven't cleaned the LP in question yet. I guess it's time already!

You should be "cleaning" every time you play it. At least with a Discwasher or something similar.

[baldrick]

You should be "cleaning" every time you play it. At least with a Discwasher or something similar.

ACK!  Dishwasher?
No fluids, please, without subsequent rinsing and drying.  I don't believe for a second that a Discwasher record brush does any cleaning at all, just losing wet dirt around.
Use a carbon fibre brush for pre-playing dusting.

[davidc1]

ACK!  Dishwasher?
No fluids, please, without subsequent rinsing and drying.  I don't believe for a second that a Discwasher record brush does any cleaning at all, just losing wet dirt around.
Use a carbon fibre brush for pre-playing dusting.

Look baldrick, I'm just trying to offer some constructive suggestions. The fact that the OP has a myriad of gizmos for his turntable, yet didn't know he should be cleaning his LP before every play shows that he does need some education. Just as he asked for.

If he could actually "see" gunk being brought up from the grooves by increasing his tracking force this shows that the record is massively dirty. Incredibly dirty.

The fact that it only happens with one LP in one spot shows the problem has nothing to do with his system, and everything to do with the LP itself. Hence, my suggestion of cleaning.

Your suggestion of using a "carbon fibre brush" doesn't help much without a recommendation of a brand and how to use it.

Poor quality carbon fiber brushes can scratch the LP (carbon fiber is much harder than vinyl). Also, using a carbon fiber brush without an adequate electrical connection to ground can create a huge static charge on the record. Attracting more dust, and possibly even a static discharge that can damage his cartridge (think of about 10,000 volts in a cartridge that is designed to output 3.5mV).

Regarding the Discwasher...first, better than nothing.
If we assume that today's Discwasher is the same product from the 1970's-80's (I have no idea if it is), then I can assure you it's been tested and analyzed many times over by all the old mags (High Fidelity, Stereo Review, Audio, Stereophile, Absolute Sound, etc.) and has been found to work well. There are better ways I'm sure. Again, I have no idea if today's Discwasher is the same construction as from 40 yrs ago, but it's better than doing nothing. Use the Discwasher with whatever fluid you think is best.