IDOC_ADAPTER and username

Has anyone seen this before? I've checked all the RFC connections and everything I can think of, but haven't found any bad users...

<SAP:Category>XIAdapter</SAP:Category>

<SAP:Code area="IDOC_ADAPTER">ATTRIBUTE_IDOC_METADATA</SAP:Code>

<SAP:P1>Name or password is incorrect. Please re-enter</SAP:P1>

<SAP:P2 />

<SAP:P3 />

<SAP:P4 />

<SAP:AdditionalText />

<SAP:ApplicationFaultMessage namespace="" />

<SAP:Stack>Error: Name or password is incorrect. Please re-enter</SAP:Stack>

<SAP:Retry>M</SAP:Retry>