strange number corruption on pdp11/34

Hi, I'm getting all zeroes nearly any time there's supposed to be a large number output to my terminal. Does this sound familiar to anyone? This happened last night on rsx and is also happening today on xxdp. example xxdp testing rl02: DRSSM-G2 CZRLK-B-0 CZRLK PERFORMS RANDOM OPERATIONS OF GET STATUS, SEEK, READ, AND WRITE UNIT IS RL01,RL02 RSTRT ADR 000000 DR>START CHANGE HW (L) ? Y # UNITS (D) ? 1 UNIT 0 RL11 (L) Y ? Y BUS ADDRESS (O) 0 ? VECTOR (O) 0 ? DRIVE (O) 0 ? DRIVE TYPE = RL01 (L) Y ? N BR LEVEL (O) 0 ? CHANGE SW (L) ? N NXT TST MAY ZERO LD UNIT. DOIT ANYWAY?Y TESTING STARTED CZRLK HRD ERR 00000 ON UNIT 00 TST 000 SUB 000 PC: 000000 DR ERR TIME: 00:00:00 RLCS: 000000 DRIVE: 0 DRIVE TYPE = RL00 BEFORE ERR (RLCS): 000000 (RLBA): 000000 (RLDA): 000000 (RLMP): 000000 AT ERR (RLCS): 000000 (RLBA): 000000 (RLDA): 000000 (RLMP): 000000 DR ERR ADDR = CYL: 000. SUR: 0 SECT: 00. STATUS WAS: 000000 LST POS: 000000 DR ERR - RECOVERED CZRLK HRD ERR 00000 ON UNIT 00 TST 000 SUB 000 PC: 000000 DR ERR TIME: 00:00:00 RLCS: 000000 DRIVE: 0 DRIVE TYPE = RL00 BEFORE ERR (RLCS): 000000 (RLBA): 000000 (RLDA): 000000 (RLMP): 000000 AT ERR (RLCS): 000000 (RLBA): 000000 (RLDA): 000000 (RLMP): 000000 DR ERR ADDR = CYL: 000. SUR: 0 SECT: 00. STATUS WAS: 000000 LST POS: 000000 DR ERR - RECOVERED CZRLK HRD ERR 00000 ON UNIT 00 TST 000 SUB 000 PC: 000000 GARBLED DATA - CAN'T CHECK IT TIME: 00:00:00 RLCS: 000000 DRIVE: 0 DRIVE TYPE = RL00 BEFORE ERR (RLCS): 000000 (RLBA): 000000 (RLDA): 000000 (RLMP): 000000 AT ERR (RLCS): 000000 (RLBA): 000000 (RLDA): 000000 (RLMP): 000000 DR ERR ADDR = CYL: 000. SUR: 0 SECT: 00. XFER SIZE = 00000. WORDS 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000 000000