Can i put IR Shell on 5.50 GenD, with prometheus v4

[Jaecus]

I have been looking around and getting confused as to if this is doable or not.
Can I put IR Shell on 1000 Phat psp 5.50 GenD, with prometheus v4?
I have tried to put IR shell v4.9 on and when i launch it gives me this message:
Unsupported firmware version detected pls power off psp
and I have to remove memory stick to reboot else the message is displayed on boot. I dont know if i have installed it correctly, I did this with the 3 folders in the IR shell package:
IRSHELL - copied to root of MS
seplugins - contents copied to seplugins
PSP/Game and Game150 - contents copied to PSP/Game and Game150

maybe this version doesn't work with my firmware, or no IR shell does, or i installed incorrectly. Can anybody tell me if i have done it wrong or point me to another version that should work?
thanks

[Jaecus]

ah i looked some more and found a v5.2 version for 5.50, and installed in the same way, seems to work ok now, thanks anyway