postgres crash SOS

Hi all,

I use 8.2 on a windows server 2008.
Suddenly postgres crashed and I can not do anything. The message is
Could not access status of transaction 3982736.
DATAIL: Could not read from file "pg_clog/0003" at offset 204800: No error.

The only one thing I found to correct this is to create a file filled
with binary 0 and replace clog/0003. Both files size are the same. I
tried that but I am still not able to run vacuum. I tried even with a
bigger empty clog/0003 file, but nothing.
I tried to drop the last few transaction with pg_resetxlog and hoped I
can save some data, but the service wont start.
The last error message is:
ERROR: could not create relation 1663/0/1224: File exists. I looked
for base/1224/0/1663, base/1663/1224/0 and base/1663/0/1224 file but
there is no such file.

Can anyone suggest something?
Many data would be lost if I can not repaire that so please!

Thanks,
fenor