2000 to 2003 upgrade - repadmin error!?

[adder]

Hi, I'm getting the following result after issuing
REPADMIN /REPLSUM /BYSRC /BYDEST /SORTELTA

Replication Summary Start Time: 2005-01-04 15:48:17

Beginning data collection for replication summary, this may take awhile:
..........
Source DC largest delta fails/total %% error
XXXBDC >60 days 3 / 14 21 (1396) Can't
retrieve message string 1396 (0x574), error 1815.
XXXPDC 04h:45m:52s 1 / 9 11 (1753) Can't
retrieve message string 1753 (0x6d9), error 1815.
XXX04 01h:53m:11s 0 / 20 0
XXX05 01h:53m:10s 0 / 12 0
ZZZ01 01h:00m:19s 0 / 3 0

Destination DC largest delta fails/total %% error
XXXX01 >60 days 4 / 13 30 (1396) Can't retrieve
message string 1396 (0x574), error 1815.
XXX05 01h:00m:24s 0 / 8 0
XXX01 58m:02s 0 / 10 0
XXX04 55m:31s 0 / 9 0
XXXBDC 53m:50s 0 / 9 0
YYY01 53m:41s 0 / 4 0
XXXPDC 02m:39s 0 / 5 0

Any gurus out there got any pointers to tracking down the 'delta delays'
or any idea as to the error codes as I can't find any references to
these out there!!! Is it safe to proceed with the upgrade without
resolving this? All other checks look ok...

TIA