I would try 3 things first is make sure that each conduit run is fully connected and every part of that run has the same thing in comments. If you have 2 runs with the same name that can possibly mess up the sort and group of the script. The second thing to try would be to separate out the script a little bit to do this I would make a script that will only set the conduits and then make a script that will only set the conduit fittings. I’m not sure that will make much difference but it may work and if it does work you can then copy those two scripts into one script so that it can run at one time. The third thing to look at is if you have items that are made as a “Conduit Fitting” that are not a conduit fitting such as a J-box that doesn’t get connected to a run and doesn’t have the comments filled in then you will need to filter those items out before trying to set conduit fittings otherwise it could have more items in the list and not order it correctly.
On a second note I have abandoned this script in my day to day routine I have found that using CTC Express Tools with a tool called Spreadsheet Link will accomplish the same result but faster by allowing me to use excel formulas to do the same thing I was trying to do. It is a little more technical and requires a good knowledge of excel formulas. The main reason for using spreadsheet link is I don’t have to worry about a list getting scrambled into a wrong order.
Hope this helped.