I often catch extremely large numbers of pidgey's (120+) so that I can use them with a lucky egg. I've found that upon reaching around 100 or so (not clear when), if I try to sort by ID and then sort by CP or level, the client will crash. It doesn't always happen, though I can generally tell that it will because when I sort by ID, and it switches to highest ID first I can end up with a big blank area at the top, before the first Pokemon listing. If I switch it back to lowest ID on the bottom and sort by CP, crashes 100% I think.
Note that it is generally after playing for awhile that it happens, not when I first log in.
Note that it is generally after playing for awhile that it happens, not when I first log in.