At 2/27/2002 09:16 PM +0100, you wrote:
>This is a forum devoted to phonetics, not to historical linguistics, so
>this discussion is slightly OT (we could continue it on Cybalist). The PIE
>syllabic nasal *n has the following _regular_ reflexes:
>Indo-Iranian a, Baltic in, Slavic In, Greek a, Latin en, Welsh an,
>Germanic un, Armenian an, etc.
>PIE *n- (negative prefix) > Skt. a-, Gk. a-, Lat. in- (< *en-), Gmc. *un-
>(Eng. un-), Arm. an-

That is the expected regular reflex in Slavic is e~ < In- < *n. How are
present forms ne-/ni- explained?