Yep, 45 minutes a day is all we're getting some days. We were getting very early wakings and eventually fixed it by keeping a BT of 7.30 even after a short nap. Previously we'd been doing an early BT with a short nap, and a normal BT of 7.30pm with a longer nap on the days we got them, but both resulted in antics at bed and nap time and a 5.30am WU. It's all here -
http://babywhispererforums.com/index.php?topic=216320.msg2307596#msg2307596Since then, I've been capping her nap to 1 hr when we need to but some days she only has 45 minutes anyway. If I let her sleep more than an hour (even by 10 minutes), she shortens her night. The days she wakes after 45 minutes she adds another half hour to her sleep at night.
Our current routine (on a 45 minute nap day) is:
WU: 7am
Nap: 1 - 1.45pm
BT: 7.30pm
On a 1 hr nap day it's the same but we usually get a 6.30am wake up the following day, and if we let her nap 1hr 10 we get a 6.15 wake up the next day it seems. So she's getting just under 12 hours in a 24 hour period.
She has always been a bit low sleep needs and has dropped all her naps at least a month or two earlier than her friends so I'm not surprised she's a bit early to drop the amount of sleep she needs but I'm still paranoid she's not getting enough! She seems very happy when she wakes up most days, but is getting tired by bedtime now, which is often when she can get touchy and demanding if she doesn't get her own way. We're not getting full on tantrums but she's definitely touchy at that time now whereas before she just wanted to stay up!