Alaph/Yudh Discrepancy in Aramaic

[Karl]

Shlama `amkhon,

I've noticed a spelling inconsistancy between some words in the Peshitta and elsewhere. The difference is usually between alaph and yudh as the second letter of the word:

Kepa ("rock"):

• [font="Estrangelo (V1.1)"]0p0k[/font] (Peshitta)
  
• [font="Estrangelo (V1.1)"]0pyk[/font] (elsewhere)

Khera ("free"):

• [font="Estrangelo (V1.1)"]0r0x[/font] (Peshitta)
  
• [font="Estrangelo (V1.1)"]0ryx[/font] (elsewhere)

Kena ("just"):

• [font="Estrangelo (V1.1)"]0n0k[/font] (Peshitta)
  
• [font="Estrangelo (V1.1)"]0nyk[/font] (elsewhere, but this spelling means "nature" in the Peshitta)

Resha ("head"):

• [font="Estrangelo (V1.1)"]04yr[/font] (Peshitta)
  
• [font="Estrangelo (V1.1)"]040r[/font] (elsewhere, also seems to be the equivalent in Arabic and Hebrew)
  
• [font="Estrangelo (V1.1)"]04r[/font] (common modern spelling, also is (was) used on Alan Aldawood's site)

So I'm wondering what the reason behind the different spellings is. Does it have to do with dialectal difference, changing the state of the noun, or something else entirely?