i dont have a msp, but my dx has the same problem...cooling is going down few drops at the time...well, this has been like this since 2004. i replaced the coolant reservoir last year, and all the hoses too...
finally, it happens that i do have a very (but very)small leak on the radiator..well,i am just going to replace now (found one on ebay)...
so,anyway, the car runs more than fine for the last 3 years with this little leak...drove from FL to CA and return,and the car has more than 115000 miles on it!!!!!!reading this thread, it seems to me that all protege use a little coolant,nothing wrong with that!!