http://psxeboots.com/pops-compatibility-list

seems to be a common issue

No idea because of a dribble in the notes if the game was ever fixed or not, almost as bad as your post

Tested on 3.71 M33-4 by GamerbyDesign.
I´m using a PSP-Slim with 3.90 M33 and it freezes on the Flutter if you go down the second ladder and try to go up again, the game even turn off my console, I tried the saulcomcor´s EBOOT and making my own with IceTea 1.3 even used Popsloader 3.80 (Full) with the FW on 3.71, but nothing, you can´t go up the ladder and you need to do so a little further in the game by VoltKaizer.
Experienced ladder glitch using 5.00m33-6, 3.71, and 4.01 via Popsloader. Eboot made with PSX2PSP v1.4.2. -Blocken
PSP Slim 5.00 m33-3 eboot created using PSX2PSP v1.4.2. everything seems 2 be fine and well tested… -phantomrenegade-
5.00 works great (tested not completed) – DebugJunky
5.00 Ladder crash glitch seems to happen to ALL ladders, including the Flutter ladder to leave Pokte Village (first key island) -Dragunhart
3.52 Fixes pokte ladder crash, recommended pops version to bypass glitch. -Dragunhart
All verions 3.40-5.00 tested Crash at second flutter ladder. (Any version 3.30 and below cannot load saved data 3.30+, and game freezes when you use the second flutter ladder to go up) -Dragunhart
Ladder glitch fixed in CFW 6.20 PRO-B4 finally.
P.S. firmware itself fixes nothing but the pops engine will