If the device is a certified quantum LTO3 device then the following will apply per the Quantum Website:
Quantum LTO-3 tape drive solutions offer industry-leading performance with 800GB* of capacity on a single cartridge and backup speeds of 324GB/hr*. Backward-compatible and interchangeable with all LTO generations and manufacturers, the LTO-3 offers outstanding investment protection in enterprise environments.
if i am not wrong it should not happen like that..it should be down ward compatibility…so means lto 3 can read lto 2..
can you try other lto2 tapes?