Htc pg58130 format code !

BlackBerry 9300 Faulty, BARGAIN.
UNLOCKED BlackBerry 9300, got a blue back cover and a shiny blue housing like the picture. The ERROR is that i recently entered an unlock code from a site, i payed for it and entered it and it worked great for about a week but now it says 'Phone does not allow MM6' Now i dont have a clue how to sort this or what it meanss but i think its blocked so maybe its good for abroad or somebody can fixx it? :) so maybe somebody else will know so... 40 quid collection or swap for other blackberry like 8520? :) RING ME OR EMAIL ONLY NO TEXTING. thnx email without the gumtree stuff - joshparley at gmail . com