No Supply Cap on 2 provinces:

[unmerged(11746)]

Ellice Islands and New Hebrides Islands have no supply cap on them... (when empty of troops)

thus if you supply them with just oil and supplies they will continue to soak up both up to 9999.

(All others stop after first delivery where there are no troops present)

 

[Kevin Mc Carthy]

This may be the problem I described as "islands generating supplies" in two other threads.

 

[unmerged(11627)]

It appears as if Palau also can recive loads of oil & supplies as well.