Hi Steven,
Having a thread in "Locking Resource" does not mean there is an issue unless it does not stay in that state.
I don't know how does "Bradmak" to determine when to report this error, but if it just issue an "admin who" command and check the status of each thread, it is possible it had seen that in a snapshot only.
Now, if the state remain, it could be a lake of resource or cache size undersized.
In such case, it's a better practice to run and collect several "admin time admin who admin who,sqm admin who,sqt" to check how things are "moving" in SRS including threads status, Queue markers and other counters reported here.
Regards
Yvan