Invalid block header IBH - yet again!

We are using 11.1.2.4.000 on Linux. Our essbase application database size is about 40gb BSO after defragmentation (export/import/agg). fragmented db size goes somewhere about 60gb plus in 5 days. here are some key stats os db

GetDbStats:

-------Statistics of xxxxx:Plan1 -------

Dimension Name                   Type    Declared Size  Actual Size
===================================================================
ACCOUNTS                         DENSE   2749           1968
TIME                             DENSE   159            35
YEAR                             SPARSE  12             11
SCENARIO                         SPARSE  37             33
CURRENCY                         SPARSE  36             29
Region                           SPARSE  114            111
SOURCE                           SPARSE  220            186
VERSION                          SPARSE  95             85
LE                               SPARSE  221            220
ORG                              SPARSE  1428           1147

Number of dimensions                                 : 10
Declared Block Size                                  : 437091
Actual Block Size                                    : 68880
Declared Maximum Blocks                              : 1.20186887813E+016
Actual Maximum Blocks                                : 6.4300002332E+015
Number of Non Missing Leaf Blocks                    : 93938
Number of Non Missing Non Leaf Blocks                : 15892677
Number of Total Blocks                               : 15986615