1965 Mustang 4 Speed (shifter/transmission problem)

I would appreciate any advice regarding the cause of the following problems.  Thanks.

Problem 1: While taking off from a normal stop, the transmission occasionally pops out of 1st gear.

Problem 2: While upshifting from 1st into 2nd gear, with moderate effort, the transmission occasionally "misses" 2nd gear. When this occurs, I can hear a slight spinning sound (gear/bearing/syncronizer?).

The engine runs fine (no stumble or hesitation). The clutch is properly adjusted (~1 inch free travel). The upshifts from 2nd into 3rd gear, and from 3rd into 4th gear are smooth, with no problems.  

Try adjusting the shift likage
1. Loosen the three shift linkage adjustment nuts.Install a 1/4 inch diameter
alignment tool though the control bracket and levers.An alignment tool can be made from 1/4 drill rod bent to "L" shape.The extensions should be 1 1/2" and 3 3/4" from the elbow.short end of the alignment pin should beinserted into control bracket and linkage holes until bottoms

2. Tighten the three linkage adjustment nuts and then remove pin.

3. Check the gear shift lever for a smooth crossover.

        Good Luck