As this is not a BOINCstats bug I moved the topic to the Einstein forum.
The 'einstein' account is matched up with the BartS accounts because the CPID's match. Below is an extract from the Einstein XML file:
<user>
<id>6470</id>
<name>einstein</name>
<country>None</country>
<create_time>1106400423</create_time>
<total_credit>253.332823</total_credit>
<expavg_credit>26.789613</expavg_credit>
<expavg_time>1107124433.600810</expavg_time>
<cpid>252ea3e8b7dfa4d86bdac2bcc8d3fed9</cpid>
</user>
As you can see, the name is einstein, and the country is None. None is converted by BOINCstats to International. The country for the combined stats is given by the last project processed. Einstein is last in line.
I suggest you go to the Einstein main site and change your account info.