ERROR: xlog flush request not satisfied

I'm seeing the following error in 7.4.6. It first surfaced
after remounting a SAN mount from one box to another and
then running 'vacuum full':

pg_dump: ERROR: xlog flush request 68/7D853080 is not satisfied --- flushed only to 0/15A90A8
CONTEXT: writing block 34 of relation 17156/1470533
pg_dump: SQL command to dump the contents of table "patient_demographics" failed: PQendcopy() failed.
pg_dump: Error message from server: ERROR: xlog flush request 68/7D853080 is not satisfied --- flushed only to 0/15A90A8
CONTEXT: writing block 34 of relation 17156/1470533
pg_dump: The command was: COPY public.customer...

Here's my pg_controldata:

$ pg_controldata
pg_control version number: 72
Catalog version number: 200310211
Database cluster state: shutting down
pg_control last modified: Mon Mar 6 13:26:19 2006
Current log file ID: 0
Next log file segment: 2
Latest checkpoint location: 0/151E9C8
Prior checkpoint location: 0/14DD760
Latest checkpoint's REDO location: 0/151E9C8
Latest checkpoint's UNDO location: 0/0
Latest checkpoint's StartUpID: 20
Latest checkpoint's NextXID: 2022907
Latest checkpoint's NextOID: 26923
Time of latest checkpoint: Mon Mar 6 13:05:11 2006
Database block size: 8192
Blocks per segment of large relation: 131072
Maximum length of identifiers: 64
Maximum number of function arguments: 32
Date/time type storage: floating-point numbers
Maximum length of locale name: 128
LC_COLLATE: C
LC_CTYPE: C

Here's my pg_xlog directory:

-rw------- 1 cudba cu 16777216 Mar 6 08:25 000000680000007F
-rw------- 1 cudba cu 16777216 Mar 6 08:51 0000006800000080
-rw------- 1 cudba cu 16777216 Mar 6 09:09 0000006800000081
-rw------- 1 cudba cu 16777216 Mar 6 09:20 0000006800000082
-rw------- 1 cudba cu 16777216 Mar 6 09:30 0000006800000083
-rw------- 1 cudba cu 16777216 Mar 6 09:45 0000006800000084
-rw------- 1 cudba cu 16777216 Mar 6 10:00 0000006800000085
-rw------- 1 cudba cu 16777216 Mar 6 10:10 000000680000007E
-rw------- 1 cudba cu 16777216 Mar 6 13:21 0000000000000001

I have pg_filedump built.

Any clues on how to tweak this file to restore full access
while minimizing data loss?

Thanks,
Ed