Memory stick wont read my backups!!

[sorrow2790]

I use a sandisk 8 gb micro sd card with an adaptor.Now,the problem is that I cant run some backups.Yes,my PSP is pandorized,before you all ask!!lol!I have also changed the UMD mode to Sony NP****,but nothing...I have been told that this happens because my memory stick does not support magicgate...Is it true??I have tried the games that dont work in mine in my brothers memory stick (sony original with magicgate) and they work perfectly...Isnt any way to solve this??