Bottle carbonation issues / questions

Hey all.

I have a relatively flat porter and had a few questions for everyone. I bottled 2 different 5-gallon batches of beer 1 week apart. One has a decent carbonation level and the other is pretty flat. Here are some of the details:

Batch 1 - Pumpkin Honey Porter. Brewed 9/30/12, secondary 10/4/12, bottled 10/21/12, OG 1.052, FG 1.010, Priming sugar: 3/4 cup dextrose

Batch 2 - Dunkelweizen. Brewed 10/14/12, bottled 10/27/12, OG 1.040, FG 1.008, Priming sugar: 1 cup dextrose

Just after bottling the porter, the temperature dropped outside dramatically and also in my basement (where the bottles are kept). Typical temperature for the basement is 70 deg. When the colder weather came, the basement temperatures dropped into the mid-50s briefly and was probably in the low 60s when I bottled the dunkelweizen. 10 days after bottling the porter, I opened one and noted its low carbonation level. I then realized that the basement temp was the likely cause and I added a portable heater to the room and have since kept the temp at 72 deg.

Several days after adding the heater, I opened one of each beer. The dunkelweizen was decently carbonated but the porter is still pretty flat. My question here: Does it make sense for one beer to carbonate faster than another?

What I think happened is that the porter yeast became inactive and settled on the bottom during the coldest week before bottling the dunkelweizen and is slow to wake up. Recently, I have swished the porter bottles around to get the yeast back in suspension but it seems to settle back on the bottom. Second question: Should I shake the bottles a little more vigorously one more time? Third: Do you all expect that adequate carbonation will come in time or should I think about adding yeast or sugar tabs to the bottles at some point down the road if I see no progress?

Thanks!
--Paul

They will carb up eventually,try to keep them around 70ish

Its been my experience that wheat and lower gravity beers will carb up faster then mid or higher gravity beers. I made an English mild (3.3% alc) that was fully carbed in one week while the Belgian Christmas ale (7.4% alc) I bottled a week earlier was no where near ready. That one took 3 weeks. Right now my cellar is holding my fermentation temps at 65 which for me is perfect. I generally leave em upstairs for the first week of bottling and then take em downstairs to finish.

Thanks for the feedback. I'll give it a couple of weeks and open another and let you all know how it goes.

Just wait it out, it'll get there.

I also agree with Glynn, my weizens carb almost overnight. I think it's because hefeweizen yeast has such low flocculation, there's tons of it in suspension so it works fast. I just bottled an 8.5% abv weizenbock, after a week it's carbed already.

All FYI... After a bit more time I opened one up for Thanksgiving and it was well carbonated! Thanks again for the feedback. Also, I mentioned this experience to one of the guys at my local homebrew store and they said letting the bottles sit in a tub of warm water for a day will get the yeast to wake up. I did not need to try it but I wanted to throw that out there in case anyone else has a similar issue.