the UMD housings can be a hindrance, as well as protection.
he disk is the same as any optical media, dvd in this case. (albeit, a custom storage capacity, 2g a disk.)
as long as the actual disk and drive lens is clean, should make zero difference.
still, does this 'third party' housing grip the disk too hard?
if so, that will slow the motor down, stress it, create stream timeouts.
compare the disk to one still in original $ony UMD housing, if it still spins with the same consistency as an original, look at the disk itself for imperfections/scratches or dirt...and maintain.
outside that, the optical drive could be the issue?
one way to check the disk, is dump the UMD as a single file (iso) via pspfiler.
if it dumps without shitout, it's fine.
if the operation self-terminates, possible:
1, disk gripped too hard by the third-party housing slowing data transfer.
2, optical disk itself is scratched.
3, or the lens needs cleaning/potentiometer adjusting?.
