I don't know exactly what your problem is, but I would look into decreasing the size of your upload. Of course it depends on a lot of factors, but ours is under 20MB. Not including images, for example, makes a huge difference.
From the commissioner portal screen there is a league file settings button that you can press which will bring you to a screen that allows you to select what you want to upload or not upload. You probably want to include things like messages, etc for the last few sims though as otherwise if a member misses one update then they'll miss all those, but the images and a couple dats are not necessary every sim.
There are various threads on the commissioner boards (not just the OOTPX board) on the subject as well that you should maybe check out. There are probably more, but some are:
http://www.ootpdevelopments.com/boar...file-size.html
http://www.ootpdevelopments.com/boar...40mb-10mb.html
http://www.ootpdevelopments.com/boar...-download.html
http://www.ootpdevelopments.com/boar...ween-sims.html
What we do is after every sim we upload a sim update file, the same one that the game uses to update in-game, and this file is under 20MB. We also provide a base file that just includes all the dats as the update file doesn't include all the dats you need to load the league. This base file people only need when they first join the league or if they need to reinstall for some reason. About the only other file that's needed is an images file that we update maybe once a season. I figure that's probably about as good (size-wise at least) as you can do it.