I am seeing a lot of these at the moment on my PC as well as my Mac.
<core_client_version>5.4.9</core_client_version>
<message>
process exited with code 250 (0xfa)
</message>
<stderr_txt>
SETI@home error -6 Bad workunit header
!swi.data_type || !found || !swi.nsamples
File: /Users/alexkan/seti/seti_boinc_tarball/client/seti_header.cpp
Line: 210
</stderr_txt>

Anyone else getting these or is it just me? If its not just me, why?
K.