I am yet to have issues with my magic 3.1 on my v4. Substance plays great, kaliso rips no problem, loves whatever i throw at it first boot everytime. Then i again i did a rather unorthodox install so that might have helped.
JAP 60GB PS3 (release date)
37000 L V7 Ocean Blue Matrix Infinity BB Navi (.32)
30001-R V4R Magic ICE 91f3+ PS2 Linux (2.4.1)
10000 V0 No Mod, PSP-1000 1.0 FW 100K release model
PS2 Linux Kit (BB Navigator Installed)
Scph-5501 Stealth, All Sega Systems
Cube with Save, Xbox 1.0 Modded