Cannot read block 348938 of pdbsynchtable

Dear All ,

I am using postgres 7.3. on RHEL 4.0

If I do any operation(select , delete , count , update , vacuum,reindex) on a table ; the error comes "Cannot read block 348938 of pdbsynchtable"

Given below is the o/p of the files corresponding to the table

-rw------- 1 postgres postgres 1073741824 Apr 7 10:56 25205
-rw------- 1 postgres postgres 1073741824 Aug 29 2009 25205.1
-rw------- 1 postgres postgres 1073741824 Mar 30 12:32 25205.2
-rw------- 1 postgres postgres 1048674304 Apr 7 10:55 25205.3

I some blogs its given that this problem occurs due to bad sectors on disk and the resolution given is reidexing, vacuuming the table or restoring to the last backup.

In my case neither the table is getting reindexed nor vaccum ,even i am not able to get the count of the recordss in the table. There is no option of restoring to backup as i dont have one.
Even if If i try to pad the file 25205.3 using DD command I am not able to calculate the bytes to be padded as the total count of the blocks is comming out to be 521228 and the error is coming cannot read the 348938 block.

Kindly help in identifying and solving this problem.

Regards,
Utsav
Disclaimer :- This e-mail and any attachment may contain confidential, proprietary or legally privileged information. If you are not the original intended recipient and have erroneously received this message, you are prohibited from using, copying, altering or disclosing the content of this message. Please delete it immediately and notify the sender. Newgen Software Technologies Ltd (NSTL) accepts no responsibilities for loss or damage arising from the use of the information transmitted by this email including damages from virus and further acknowledges that no binding nature of the message shall be implied or assumed unless the sender does so expressly with due authority of NSTL.