No coincidence.
That was your MSAFE coins arriving via the Master Protocol! You should be able to check your balance for that address using
masterchest.info.
(FYI 0.000055 just means that mastercoin-tools/omniwallet was used to send it - each implementation uses a different amount to carry the Master Protocol metadata).
Thanks udecker. I didn't realize that the Master Protocol requires a minimal amount of BTC to carry the payload....makes sense, but I wasn't aware of that.