unless you're Afghani, i'm sorry to hear you're in Afghanistan. I hope you get out soon.
unfortunately, Sprint + GSM "does not compute". In the US, Sprint is CDMA and their phones don't have SIM cards here. I don't know what kind of service Sprint offers internationally, but it seems you're saying they offer GSM service, which i'm pretty sure is the standard internationally and that may explain why they have it there.
with GSM, its also critical which band (Mhz) your carrier uses and the phone can receive. Example: in the US, T-Mobile has proprietary access to the 1700Mhz band, so only T-Mobile branded phones bother to include a receiver for that band, and T-Mo puts their best service on that band to maintain the exclusivity which allows them to profit from handset sales.
i can't imagine why you'd need to reprovision a phone so often. why would a phone "lose" the required settings? it should be saved to the SIM. i can't imagine why a webOS phone would behave differently from the Motorola you have, if they're receiving the carrier on the same band....unless you have a defective unit of course. then yeah, a non-broken phone would work better than a broken one. (obviously)
you may find more info on a Sprint forum in a nearby country, so search for something like that
. particularly if you don't have access to carrier service center there to diagnose your phone and determine if you only need a new SIM card or a reflashing of the device.
good luck, and take care of yourself over there.