GDB memory examination output off by 8 bytes compared to actual memory content

I'm experiencing a weird inconsistency between the memory dump output I get from GDB's x command when dumping memory several KB into a complex C++ object. At the GDB prompt I get:

(gdb) x/32b 0x7FFFCD82B000
0x7fffcd82b000: 0xf8    0x23    0xae    0xf2    0xff    0x7f    0x00    0x00
0x7fffcd82b008: 0x00    0x00    0x00    0x00    0x00    0x00    0x00    0x00
0x7fffcd82b010: 0xff    0xff    0xff    0xff    0x00    0x00    0x00    0x00
0x7fffcd82b018: 0x00    0x00    0x00    0x00    0x00    0x00    0x00    0x00

And this corresponds to abnormal values of object members, e.g. bools with values other than 0 or 1. However, When dumping the content of this memory area from /proc/pid/mem I get 0 in the first 8 bytes and then the same memory content as above (the left column is the memory offset in decimal):

 0  0
 1  0
 2  0
 3  0
 4  0
 5  0
 6  0
 7  0
 8 f8
 9 23
10 ae
11 f2
12 ff
13 7f
14  0
15  0
16  0
17  0
18  0
19  0
20  0
21  0
22  0
23  0
24 30
25 21
26 4c
27 f4
28 ff
29 7f
30  0
31  0

I'm using GDB 7.7.1 on Linux 3.13 (Unbuntu 14.04). My code is C++ 11 and I compile using g++ 4.8.2 that came with the system.

The Python script I used to dump the content of /proc/.../mem shown above:

fp = open('/proc/24821/mem', 'r')
fp.seek(0x7fffed82b000)
r = fp.read(32)
for n, c in enumerate(r): print '%2d' % n, '%2x' % ord(c)

Any help will be greatly appreciated!