Cobble Hill Afghan (Crochet)

My first crochet pattern using this yarn called for Size K. I got through it but not w/o problems: often times the hook would not grab the thin thread that is of a different fabric than the remaining threads. The other problem I encountered is this thin thread was unwrapped/unattached and the result was ballooned yarn. I just finished an afghan with Size P and that is much less problematic. Problems aside, the finished product on both projects is great.