Most off-to-the-shelf Bluetooth stacks are pretty terrible... the only reason ours was decent was become we built it from stack before Bluetooth was so pre-dominant. Ours had some issues because we were behind the spec (the guys at the top only wanted the features that supported the spec, no cutting corners, no pretending the features worked, it had to work correctly)

Source: Worked Radio Verification at a mobile company that developed it's own bluetooth stack. RIP Blackberry.