I purchased my Ultradeck in November of last year but I haven't used it much until recently.
I was playing a brand new LP and then a used LP and they both repeat skipped around the same place so I got out my flashlight to take a look at the setup of the tonearm.
Whilst looking about, I noticed a jagged round space on the tonearm base that was a light silver while the rest was black.
I googled some photos of the Ultradeck and found that there is a protrusion about 1/2" high which stops the tonearm from migrating too far into the center of the record. Mine was broken off.
I drove down to my dealer with photos in hand and they explained what had happened.
Apparently, some owners complained the tonearm stop was preventing the tonearm from reaching the end of the recording space sometimes.
Mofi's response was to snap the tonearm stop off and ship the units with the jagged stump.
Since it actually looks broken, I contacted Mofi. They responded the next day and said they'd retooled the mold and the tonearm stop had been moved so it didn't impede tonearm movement prematurely and would be happy to trade out my deck for a new one with the fix. They were going to provide a shipping label and once they received my deck, they would send out the new and improved version.
Unbeknownst to me, my dealer was in touch with them and they had some new decks in stock and would trade mine out and deal with returning my deck to Mofi so I didn't have to.
Ugly stump problem solved!