caSTaway 006 Help!

Maybe someone can hlep me because I think I am going mad!
I am setting up a new MS full of emu's for my M33-3 Slim and have put on caSTaway 006, but despite never having problems in the past with previous versions of caSTaway, and usually being able to figure trickier PSP stuff out (downgrade, pandora etc!), I cannot get the bloody thing to work!
I have tried it in all three GAME folders (currently in GAME371) and have the TOS.ROM in the ATARI_ST folder which is in GAME371 along with the program directory, but when I run it on the PSP it says no TOS.ROM found and crashes the system!
I just installed it on my 3.40 phat (in GAME340) and it does the same!
I have tried TOS roms from two different sources and really have no idea what the hell is going on.
What am I doing wrong???!

Surely someone has installed caSTaway 006 successfully and can help me?
90 odd people have looked, please can someone reply!
Cheers,
Paul

OK, just figured it out - seems to be a bit 50/50, so here I go incase anyone else needs help in the future.
1) Make sure you rename the TOS.ROM extension! I was doing this in Windows and did not realise the extension was remaining as .IMG, so it was TOS.ROM.IMG!
2) But taking the above into account, the install instructions are far from clear - I put this in my GAME371 folder once I had renamed the ROM properly, and it still crashed! seems you need to have the ATARI_ST folder inside the plain old GAME folder (even though caSTawayPSP folder is still in GAME371) - it now runs fine!