>or it could be simply that you have not yet told the auto-magic marshaling builder
The 32-bit problem manifests itself even when I am not using marshalling to get the string values - I pass a single pointer to the callback and (minimally) use something like this:
```
{
string[] values = new string[n];
string[] names = new string[n];
int ptr_size = Marshal.SizeOf(typeof(IntPtr));
for (int i=0; i<n; i++)
{
IntPtr vp;
vp = Marshal.ReadIntPtr(values_ptr, i * ptr_size);
values[i] = util.from_utf8(vp);
vp = Marshal.ReadIntPtr(names_ptr, i * ptr_size);
names[i] = util.from_utf8(vp);
}
```
where values_ptr is a single pointer for values & the corresponding pointer for column names is names_ptr; n is the number of columns.