smurfette,
im watching this with interest as our DS is a month younger than your LO but exactly the same is happening. roughly two NWs a night (we have it now so he just takes a sip of water from a botttle for about 10secs and goes over again, but the EW are crazy, this morning it was 450am and that was him for the day! i tried to put him back over for an hour but to no avail. and this after getting 550am out of him for 2 days in a row. Kara gave us that advice which we tried re the nap times and we are sticking to them, but sometimes it just seems hopeless as the goal posts are constantly moving with his WU times, how does this affect his nap times, will he then be UT/OT etc etc. there always seems to be smth!
so sorry i cant help but exactly the same thing is happening to us, if i stumble across any magical solution ill be sure to let you know