Changing 1.52 fw to M33- 3.72 Custom fm.

Im running a phat psp with official 1.52 fw, modified to 1.50 using Yoshikiro's WAB Version Changer v 2.0.
Can i Upgrade to M33-3.72 Custom fw under this setting or will i screw the psp up?.
Any idea's on the best way to upgrade would be appreciated.
It's probably a stupid question, but i don't know as much about psp hacking as some of you do.

No, your true firmware isnt a 1.50 its still 1.52, all you did was edit the string to change the words to say 1.50 firmware.

Anyways, look here...
http://pspbrew.com/forum/viewtopic.php?t=9454

You'll have to upgrade to 2.71 and downgrade using the 2.71 tutorial...depending on which motherboard you have you'll have to choose the appropraite downgrader. They have all the files you'll need for the process just read carefully and double check each step to make sure you did everything right. If you ever have any questions during the process be sure to ask rather than just thinking it will work if you guess.

Once your done with that you'll have to upgrade to 3.52 m33-4, then to 3.71 m33. Theyre all included on my guide.

thanx for that info. the psp was an import from Japan long before they were available here in the UK and was fw 1.50.
I'll check out the motherboard no. ( is it behind the battery/inside the umd slot?) before i do anything drastic, and will certainly follow your links.
Ta.

If you check one of the 2.71 downgrader tutorials it will show you where too look and what to look for to see if you have a TA-082 motherboard... I'm guessing yours is probably a TA-079 since you bought yours that early but its better to be safe. But yes, you check inside the umd tray in the upper right corner.

Followed your tips and tutorial links and PSP is up to M-33 3.71-4 safe and sound.
Respect to you guys for your knowledge on all things PSP.