My F430 F1 Drops Out of Gear When Stopped

When the engine, etc. of my F430 is at operating temperature, it will occasionally drop out of 1st gear into neutral when waiting at a red light. Attempts to re-engage 1st are difficult, sometimes requiring that the engine be shut off and restarted several times. Most annoying (particularly for those trapped behind me), and my mechanic is warning that this may be a VERY expensive repair (and requiring used parts due to Ferrari not stocking many OEM components for the F430). We're now discussing a transmission swap to a manual 6-speed as a possible curative.

The car is out of town, so the error code has yet to be pulled, but I'm wondering if anyone might have encountered a similar issue? The clutch is at 50% and the car has ± 24,000 miles under its belt. Any thoughts would be much appreciated!