The only exception is if the spell can be cast automatically (RMFRP Section 14, RMSS section 26), in which case no roll is made on the SCSM (but attack spells can still fail on an unmodified roll of 01-02 on the Basic Spell Attack Table, or any modified roll that ends in a 'F' result).
Basically, if there are no *negative* modifiers from table T4-6 that apply, the spell can be cast automatically.
It must be noted that this table (SCSM) has a different set of thresholds from the normal static manoeuver table : partial success kicks in at 26 instead of 76, near success at 41 instead of 91, success at 61 instead of 111 and absolute success at 126 instead of 176 (probably because the skill rank bonus has a radically different progression from the standard one... and you can wonder why it is so, since the bonus is *not* used for the spell attack rolls - the number of *ranks* is used instead).
As a side note, it also means that a non-automatic attack roll will require up to three rolls to be resolved (and look up three tables) : SCSM, Spell Casting Attack / Elemental Attack, and Resistance Roll / Critical Roll. Up from two for a standard attack, and from one for a non-combat manoeuver. Which is, if you ask me, kind of one roll too many, at least.