Hi,
try the following query:
select
spid
, cmd
, blocked
, status
, db_name(dbid) as dbname
, hostprocess
, hostname
, suser_name(suid) as loginname
from
master..sysprocesses
where
spid = < spid of dump tran process >
The column "blocked" will contain the spid of the process which might block your dump tran process.
Best regards
Christoph