hi all, new to the forum and running, so please be gentle 
i'm in my early 40's and just started running. it was never something i enjoyed in school, but have recently taken it up as part of a general training & fitness regime and have changed my opinion completely! i mainly do 'mill running in the gym for very short distances - max 1.5 miles
i'm using barefoot daps (originally bought for gym work) and quickly learnt that heel striking does my knees no favours. tried running on the balls of the feet (is that forefoot or midfoot?), with the heel of the foot barely touching the ground, and found that it was much more comfortable, with virtually no stress on the knees. i started 6 weeks ago by slowly jogging 1/2km at about 7km/h and have 'built-up' to 1.5 miles at 8-12 km/h.
my warm-up consists of calf stretching followed by forefoot walking for about 5mins (1/2km), gradually increasing the pace. my 'run' then kicks off by setting the speed to 7km/h, working through to 12 or 13 km/h and slowing back to 10km/h for the final 40% or so. after the desired distance, i'll gradually slow the pace to a slow walk over 3 or 4 mins, then go through the stretch out described a bit later in this post.
my problem is that i occassionaly get a stabbing pain in the middle of the calf at a random time during the run, at which point i stop immediately and go into a lengthy stretching routine. this then means a week or so off, by which time there is no pain at all in the calf. based on this i'm assuming that the calf muscles (i've done the left once and the right twice) aren't pulled or ripped. if anything, it feels like an acute cramp hit.
i don't get this problem every time i run. it's happened 3 times in the last 15 or so runs. distance doesn't matter. it occurs anywhere within 500m and 2000m of starting the run.
if it's any use, this is the excercise diary for the last 2 injuries:
sat 6th oct - outdoor run. stretch in house. walk on balls of feet for 5 mins. gentle jog. left calf goes after 1/2mile
sun - rest
mon - static bike to excercise muscle. feels lots better after ride
tue - walk on mill for 1/2mile. no problems
weds - 1/2 mile jog on mill. no problems
thurs - ask one of the trainers to look at running style. do 1.5 miles on mill. foot fall was deemed to be ok, needed to lengthen stride slightly. longer stride felt a bit more comfortable. no problems
fri - rest
sat 13th - 1.5mile run on mill, right calf goes @ 1.25 miles.
now, whenever i've done any kind of training (weights, cardio etc) i've rarely, if ever, done a cool down or stretch out, which has no doubt added to the problem. since starting the running, i'll usually finish with 5 mins of calf stretching and a few minutes calf massage on a powerplate.
am i asking too much as a new runner?
is there anything i can do to stop getting these calf hits while forefoot running?
is my 'warm-up' insufficient and if so, what should i be doing?
thanks!!!