While I'm no expert on rogues, rogue with 1-2 levels or fighter (for higher hp, higher BAB, shield proficiency and extra feats) should be very viable, same for rogue with 2 levels of ranger (a bit higher hp, higher BAB, shield proficiency, favored enemy & free two weapon fighting at 2 ranger) and 1 rogue/9 bard should also work since bards also have a lot of skillpoints and share many of the same class skills as rogues (hide, move silently, UMD, ...). It would make the already versatile bard into a true jack-of-all-trades at the loss of 2 lvl 4 spells which only pure bards can get, but you have to think past lvl 10 anyways as the cap will raise eventually.