Can not mount an ext2 file system rw immediately after creating it ?

[shaulk@israsrv.net.il (shaul)]

I can not mount an ext2 file system rw immediately after creating it. What am 
I doing wrong ?

[03:41:08 shaul]# cfdisk -P s /dev/hda
Partition Table for /dev/hda

            First    Last
 # Type     Sector   Sector   Offset  Length   Filesystem Type (ID)   Flags
-- ------- -------- --------- ------ --------- ---------------------- ---------
 1 Primary        0  1024127      63  1024128  FAT16 (06)             Boot (80)
 2 Primary  1024128  2503871       0  1479744  Linux (83)

[03:43:11 shaul]# mkfs.ext2 /dev/hda2
mke2fs 1.15, 18-Jul-1999 for EXT2 FS 0.5b, 95/08/09
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
92544 inodes, 184968 blocks
9248 blocks (5.00%) reserved for the super user
First data block=0
6 block groups
32768 blocks per group, 32768 fragments per group
15424 inodes per group
Superblock backups stored on blocks: 
        32768, 98304, 163840

Writing inode tables: done                            
Writing superblocks and filesystem accounting information: done

[03:44:35 shaul]# mount -t ext2 -o rw /dev/hda2 /mnt
EXT2-fs: 03:02: couldn't mount RDWR because of unsupported optional features.
mount: wrong fs type, bad option, bad superblock on /dev/hda2,
       or too many mounted file systems

[03:50:37 shaul]# mount -t ext2 -o ro /dev/hda2 /mnt

[03:50:42 shaul]# mount | grep /mnt
/dev/hda2 on /mnt type ext2 (ro)

[03:50:52 shaul]# ls /mnt
lost+found

[03:51:44 shaul]# umount /mnt

[03:53:39 shaul]# fsck.ext2 /dev/hda2
e2fsck 1.15, 18-Jul-1999 for EXT2 FS 0.5b, 95/08/09
/dev/hda2: clean, 11/92544 files, 2917/184968 blocks



Package: e2fsprogs
Version: 1.15-3
Severity: normal

-- System Information
Debian Release: potato
Kernel Version: Linux rakefet 2.0.36 #2 Sun Feb 21 15:55:27 EST 1999 i586 
unknown

Versions of the packages e2fsprogs depends on:
ii  libc6           2.1.2-5        GNU C Library: Shared libraries and timezone

Package: mount
Version: 2.9w-3
Severity: normal

-- System Information
Debian Release: potato
Kernel Version: Linux rakefet 2.0.36 #2 Sun Feb 21 15:55:27 EST 1999 i586 
unknown

Versions of the packages mount depends on:
ii  libc6           2.1.2-5        GNU C Library: Shared libraries and timezone