I added this information as a comment to bug 2825243 but I'm not sure if it's the same so I thought I'd post it here also to see about getting some feedback:

I am experiencing widespread data corruption when restarting the
May2009-SP1 MonetDB release also, but mine is much simpler.

On 64-bit ubuntu:
Linux dsvm01 2.6.24-23-server #1 SMP Wed Apr 1 22:14:30 UTC 2009 x86_64
GNU/Linux

With a table defined as follows:
CREATE TABLE "tablespace"."test_table" (
"col1" varchar(50),
"col2" varchar(50),
"col3" varchar(50),
"col4" varchar(50),
"col5" varchar(50),
"col6" int,
"col7" timestamp(7),
"col8" int,
"col9" int,
"col10" int
);

I imported 20998687 records into this table with all columns populated and
ran a couple of queries to check the data:

select count(*) from test_table ;
[ 20998687 ]

select count(*) from test_table where col1 = '' or col2 = '' or col3 = '';
[ 0 ]

select max(col7), min(col7) from test_table ;
[ 2009-07-25 14:17:15.538000, 2009-07-24 15:29:12.524000 ]

During the time I loaded the data and ran these queries I did not restart
the database, it had been up for about 3 days I then issued:

monetdb stop db

and

monetdb start db

and re-ran the queries:

select count(*) from raw_plays ;
[ 20998687 ]

select count(*) from raw_plays where col1 = '' or col2 = '' or col3 = '';
[ 20852061 ]

select max(col7), min(col7) from test_table ;
[ 2009-07-25 14:17:15.538000, -1-01-01 00:00:00.000000 ]

This is some serious data corruption, I've lost data in the vast majority
of these records!

73,
Matthew W. Jones (KI4ZIB)
http://matburt.net