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Linux ARPs too much

PlayingExperimenting with arping, I found the following behavior:

$ sudo arping -c 1 10.202.202.254
ARPING 10.202.202.254
60 bytes from 00:0f:20:d4:07:e0 (10.202.202.254): index=0 time=196.934 usec

--- 10.202.202.254 statistics ---
1 packets transmitted, 1 packets received,   0% unanswered
$ sudo arping -c 1 10.101.2.1
ARPING 10.101.2.1
60 bytes from 00:0f:20:d4:07:e0 (10.101.2.1): index=0 time=168.085 usec

--- 10.101.2.1 statistics ---
1 packets transmitted, 1 packets received,   0% unanswered
$

wtf? 10.101.2.1 is my default gateway (running a recent Linux 2.6 kernel), so it is ok to answer ARP requests. 10.202.202.254 is bound on the same box, but on a different interface, so I don't think it is ok to answer ARP requests for that IP address on "my" interface, as it confuses some "what network segment am I on today" mechanisms.

Is there some /proc setting where I can disable this rather generous ARP behavior?