Attenuation question

I just checked gravity on a couple of brews and they both finished much dryer than expected. Here is what I have.

The first is a light hybrid ale.
All grain
Fermentis US05
Expected OG - 1.040
OG - 1.040
Expected FG - 1.010
FG - 1.000
I was shooting for a light beer for the ladies and I got a full strength beer because of the extra attenuation.

The second is a Belgian Pale
All grain
Wyeast 3522 Belgian Ardennes with a 1.2 liter starter
Expected OG - 1.048
OG - 1.045
Expected FG - 1.010
FG - 1.004

Both beers fermented pretty close to 68 degrees.

I am not concerned about this. I think it will be intersting to see how these dryer bers turn out. I am just wondering why. I have never had beers attenuate this much on me before. These happened to be my first two all grain brews. Could that have something to do with it? Thanks in advance for your thoughts.

Recipes? Mash temps? Low mash temp will increase attenuation, as will adjuncts.

Sorry. Here is the recipe info.

This is for the light hybrid ale. The mash settled at 152 and was at 149 at the end of the 60 minute mash.

Type: All Grain Date: 2/27/2012
Batch Size (fermenter): 6.00 gal Brewer:
Boil Size: 3.50 gal Asst Brewer:
Boil Time: 60 min Equipment: My Equipment
End of Boil Volume 3.00 gal Brewhouse Efficiency: 70.00 %
Final Bottling Volume: 5.75 gal Est Mash Efficiency 70.0 %
Fermentation: Ale, Two Stage Taste Rating(out of 50): 30.0
Taste Notes:
Ingredients


Ingredients
Amt Name Type # %/IBU
8 lbs 8.0 oz Pale Malt (2 Row) US (2.0 SRM) Grain 1 94.4 %
8.0 oz Caramel/Crystal Malt - 10L (10.0 SRM) Grain 2 5.6 %
1.00 oz Willamette [4.90 %] - Boil 60.0 min Hop 3 13.5 IBUs
1.00 tsp Irish Moss (Boil 15.0 mins) Fining 4 -
1.0 pkg Safale American (DCL/Fermentis #US-05) [50.28 ml] Yeast 5 -

Beer Profile

Est Original Gravity: 1.038 SG Measured Original Gravity: 1.040 SG
Est Final Gravity: 1.008 SG Measured Final Gravity: 1.000 SG
Estimated Alcohol by Vol: 3.9 % Actual Alcohol by Vol: 5.2 %
Bitterness: 13.5 IBUs Calories: 126.6 kcal/12oz
Est Color: 3.6 SRM
Mash Profile

Mash Name: Single Infusion, Medium Body, Batch Sparge Total Grain Weight: 9 lbs
Sparge Water: 1.77 gal Grain Temperature: 72.0 F
Sparge Temperature: 168.0 F Tun Temperature: 72.0 F
Adjust Temp for Equipment: FALSE Mash PH: 5.20

Mash Steps
Name Description Step Temperature Step Time
Mash In Add 11.25 qt of water at 163.7 F 152.0 F 60 min

Sparge Step: Batch sparge with 2 steps (0.02gal, 1.75gal) of 168.0 F water
Mash Notes: Simple single infusion mash for use with most modern well modified grains (about 95% of the time).

This is for the Belgian. Mash settled at 150 and and finished at 148 after 60 minutes. I did only mash for 60 minutes and beersmith called for 75.

Belgian Pale Ale
Type: All Grain Date: 3/3/2012
Batch Size (fermenter): 5.25 gal Brewer:
Boil Size: 3.50 gal Asst Brewer:
Boil Time: 90 min Equipment: My Equipment
End of Boil Volume 2.75 gal Brewhouse Efficiency: 60.00 %
Final Bottling Volume: 5.00 gal Est Mash Efficiency 60.0 %
Fermentation: Ale, Two Stage Taste Rating(out of 50): 30.0
Taste Notes:
Ingredients


Ingredients
Amt Name Type # %/IBU
8 lbs Pilsner (2 Row) Bel (2.0 SRM) Grain 1 72.7 %
1 lbs Munich Malt - 20L (20.0 SRM) Grain 2 9.1 %
12.0 oz Caramunich Malt (56.0 SRM) Grain 3 6.8 %
4.0 oz Special B Malt (180.0 SRM) Grain 4 2.3 %
1 lbs Pilsner Liquid Extract (3.5 SRM) Extract 5 9.1 %
1.50 oz Hallertauer [4.80 %] - Boil 60.0 min Hop 6 21.4 IBUs
1.00 tsp Irish Moss (Boil 15.0 mins) Fining 7 -
1.00 oz Styrian Goldings [5.40 %] - Boil 5.0 min Hop 8 3.2 IBUs
1.0 pkg Belgian Ardennes (Wyeast Labs #3522) [124.21 ml] Yeast 9 -

Beer Profile

Est Original Gravity: 1.048 SG Measured Original Gravity: 1.045 SG
Est Final Gravity: 1.010 SG Measured Final Gravity: 1.005 SG
Estimated Alcohol by Vol: 4.9 % Actual Alcohol by Vol: 5.2 %
Bitterness: 24.6 IBUs Calories: 145.8 kcal/12oz
Est Color: 13.2 SRM
Mash Profile

Mash Name: Single Infusion, Light Body, Batch Sparge Total Grain Weight: 11 lbs
Sparge Water: 1.58 gal Grain Temperature: 72.0 F
Sparge Temperature: 168.0 F Tun Temperature: 72.0 F
Adjust Temp for Equipment: FALSE Mash PH: 5.20

Mash Steps
Name Description Step Temperature Step Time
Mash In Add 12.50 qt of water at 161.4 F 150.0 F 75 min

My thermometers are blichman and they have been calibrated.

Are you taking your FG readings with a hydrometer or a refractometer? What does the hydrometer read with some distilled water at 60F?

I wonder if it's a low-level infection. I've gotten a few of those over the years. They taste fine, but after a couple months in the bottle they turn into very slow gushers. They also attenuated better than I had expected.