Yes you can migrate VM between 4.x and 5.5 hosts.
Regarding KB article you have to check if on partition #2 exist VMFS datastore see the cause details below:
Cause
This issue occurs if the ESXi 4.x or ESXi 5.0 or ESXi 5.1 host contains a VMFS on partition #2. Such a host typically contains a scratch partition on partition #2, with the VMFS partition on partition #3.
When you run the fdisk -l command, a host with an issue reports a partition layout similar to:
Disk /dev/disks/naa.600508e0000000003b4c480287e5f60c: 72.0 GB, 72000000512 bytes
64 heads, 32 sectors/track, 68664 cylinders Units = cylinders of 2048 * 512 = 1048576 bytes
Device Boot Start End Blocks Id System
/dev/disks/naa.600508e0000000003b4c480287e5f60cp1 5 900 917504 5 Extended
/dev/disks/naa.600508e0000000003b4c480287e5f60cp2 901 68664 69390336 fb VMFS
/dev/disks/naa.600508e0000000003b4c480287e5f60cp4 * 1 4 4080 4 FAT16 <32M
/dev/disks/naa.600508e0000000003b4c480287e5f60cp5 5 254 255984 6 FAT16
/dev/disks/naa.600508e0000000003b4c480287e5f60cp6 255 504 255984 6 FAT16
/dev/disks/naa.600508e0000000003b4c480287e5f60cp7 505 614 112624 fc VMKcore