Sometimes freshness is a factor. These puppies don't have an indefinite shelf life. Perhaps they were last year's batch or something along those lines.
my sis got me a case for discmas of the newly designed lil' hotties... so far so good... put some in my socks the other night when i was going to bed that i'd used on the golf course all day... they didn't stop working until about 2am...
"'There are two mantras.,' Bernard said, 'Yum and yuk. Mine is yum.'"
Tom Robbins, Still Life With Woodpecker