I've solved it by making a few changes to my workflow as I think it may have been some physical memory trouble.
- Turned of background geoprocessing (ArcSOCP ate up all my ram) - Not Solved
- Split table into 10,000 record chunks (6 tables). 2b. Worked the first time, but didnt compute all records on the 2nd table... hmm
- Closed/Re-opened ArcMap (refreshed memory usage at the same time?)
3b. Worked and computed the 2nd table properly
- Went about closing and reopening ArcMap each time I processed a table.
Now... I am left wondering if turning off background processing (ArcSOCP) was counter-intuitive. Does ArcSOCP clear its memory usage when a new geoprocessing task occurs such that my 2nd, 3rd, n'd table would process without having to close/re-open ArcMap?
The paths range in length because they are flight routes. I don't believe there is an issue due to the fact that my routes cross the 180/-180... I believe ArcMap understands how to handle those circumstances. There is no id field (that would be easy to test with a little python to fill in a column of sequential numbers).
Projection is the default WGS1984.
Anyways, I have completed what I have set out to do but I am still stumped as to why I couldn't just process the table as a whole.