Need help urgently.

I was using Slackware 9.1, kernel 2.4.26, patched the latest 2.4.26-3 kernel because of the DoS attack...

After the patched, all my partition info is gone and I cannot boot up anymore.

HD1 (this partition info all gone)
- /dev/hda1 - 64MB (Swap)
- /dev/hda2 - 5GB (OS)
- /dev/hda3 - 75GB (data)

HD2 (This partition is still intact)
- /dev/hdb1 - 5GB (OS)
- /dev/hdb2 - 75GB (data)

I can boot from the Slack 9.1 CD and mount the 2nd HD partition.
Is ther anywhere I can recover from this?

URGENT HELP:

Thanks.

Boot with Knoppix, then run cfdisk on /dev/hda and post the results. Also, post your /etc/lilo.conf and /etc/fstab.

When it booted up, on the ide section it shows

hda:
hdb: hdb1 hdb2


At this moment, I cannot even mount anything on /dev/hda because no partition can be seen.

Previously, I have been patching security patches announced by Slackware without problems.

I have tried on 3 machines, only one successful, two had the same symptoms.

Firstly, I tried on a test machine (on ide hd), works okay.
Then, I tried on one of my production machine, then this happens.
Later, I thought maybe the machine problem, tried on another test machine with similar config.
Same problem, partition table was wipe out.

Any solutions?

I redo the partition information.
Set it up as my original partition table size.

I can now backup my datas. The only problem is the nitty gritty problems after that.