Basically - profiles with wierd divots and shapes, from bad reads - bad spot reads of a 24 patch colorchecker confirmed it was reading erratically, sometimes ok, sometimes completely wrong. Presumably a flickering in the bulb or something??
Weird divots and shapes ... good description of some of my recent attempts.
Oddly enough, today I ventured down to my dealer and used there RevD EyeOne UVcut with my table, and read my targets in fine. Put my i1 back in, and it failed after reading about 60%. Delta E difference between the two devices on the patches that were read was less than .2, most were only about .1
So I decided to try reading some specific patches repeatedly to see if the i1 was erratic, set it on the white tile when asked ... error. Ran i1 diagostics - tests failed. Same test worked fine yesterday (and several days before that). It sounds like the i1 may have been flakey ... of and on .. possibly for a long time - similar to what you described.
Anyway, got my profiles made with their device, but when my dealer talked to the rep, they are suspecting the table may be one of the early ones that did have some issues.
At least things are starting to make a little sense now.