Partition problem while installing Win8.1 on MacBookPro running OSX 10.9

I am using Boot Camp v.5.1.0 (473) to install Windows 8.1 Pro and I am facing the following partition problem.

"Windows cannot be installed to this disk. This disk has an MBR partition table. On EFI systems, windows can only be installed to GPT disks."

I am using a MacBook Pro 13” Mid 2012, 2.5 GHz Intel Core i5, 4GB 1600 MHz DDR3 running OS X Mavericks 10.9.

I had 334 GB free out 500GB and have partitioned 56GB of this for Windows installation.

I am installing from a USB and I have the downloaded support software on the same USB.

I reached at the partition selection dialogue. I click on 'Drive 0 Partition 4: Bootcamp' and click Format, then OK.

When this is complete, it changes the partition name to 'Drive 0 Partition 4' and still has the warning 'Windows can't be installed on Drive 0 Partition 4. (show details)' at bottom of the dialog.

When I click ok on the warning it prompt me above error and Next button is not visible to go ahead.

Following are commands and respective output:

$ diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.1 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 443.2 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data 56.0 GB disk0s4

/dev/disk1

#: TYPE NAME SIZE IDENTIFIER

0: CD_partition_scheme *259.1 MB disk1

1: Apple_partition_scheme 225.6 MB disk1s0

2: Apple_partition_map 17.9 KB disk1s0s1

3: Apple_HFS Idea Net Setter 17.2 MB disk1s0s2

$ sudo gpt -vv -r show /dev/disk0

gpt show: /dev/disk0: mediasize=500107862016; sectorsize=512; blocks=976773168

gpt show: /dev/disk0: Suspicious MBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 976773167

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 865718952 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

866128592 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

867398128 1552

867399680 109373440 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

976773120 15

976773135 32 Sec GPT table

976773167 1 Sec GPT header

$ sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 60801/255/63 [976773168 sectors]

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 865718952] HFS+

3: AB 1023 254 63 - 1023 254 63 [ 866128592 - 1269536] Darwin Boot

4: 07 1023 254 63 - 1023 254 63 [ 867399680 - 109373440] HPFS/QNX/AUX

Please let me know if any one had any success with this problem.

Thanks,