unable to find a common currency in txn X, and that is strange

[Graham Menhennitt]

I'm attempting to diagnose a corruption I have in my GC data file (XML).
I started GC 2.3.3 with --debug and am looking through the trace file. I
seem to have lots of entries of the form:

* 19:59:40  WARN <gnc.engine.scrub> [xaccTransFindOldCommonCurrency()]
unable to find a common currency in txn
13db240e2d97ba42480b3d64eb2528fa, and that is strange.
* 19:59:40  WARN <gnc.engine.scrub> [xaccTransScrubCurrency()] no common
transaction currency found for trans="Westpac"
(13db240e2d97ba42480b3d64eb2528fa)
* 19:59:40  WARN <gnc.engine.scrub> [xaccTransScrubCurrency()]  split=""
account="Bank fee (MC)" commodity="AUD"
* 19:59:40  WARN <gnc.engine.scrub> [xaccTransScrubCurrency()]  split=""
account="Cheque (MC)" commodity="AUD"

There are 5800 of them which corresponds roughly to the number of
transactions I have in the whole file.

Can anybody please tell me whether this indicates a problem. From the
message, it looks like it is a problem, but I can't see how every
transaction would be bad.

Thanks for any help,
  Graham