doesn't recognize "!=-" (not equal to a negative value)

Version postgres 7.4.7:

Following sql

UPDATE tablename SET value = 0.0 where value!=-9.4;

results in the error message

ERROR:  operator does not exist: smallint !=- integer
HINT:  No operator matches the given name and argument type(s). You may
need to add explicit type casts.

Seems that postgres has a problem parsing a "not equal negative value".

Anybody know if this is fixed in later versions?

Paul Tilles