Just found this in my event-log after starting emule:
TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts"
This is what I get from a M$-Guy when i asked him why XPSP2 slows down programs like emule which open many connections to different destinations:
Thanks very much for responding. This new feature is one of the stack's
"springboards", security features designed to proactively reduce the
future threat from attacks like blaster and Sasser that typically spread
by opening connections to random addresses. In fact, if this feature had
already been deployed, Sasser would have taken much longer to spread.
It's not likely to help stop the spread of spam unless spammers are
trying to reach open email relays in the same way, by opening
connections on smtp ports of random IP addresses.
This is new with XP SP2 and we're trying to get it right so that it does
not interfere with normal system operation or performance of normal,
legitimate applications, but does slow the spread of viral code. New
connection attempts over the limit for half-open connections get queued
and worked off at a certain (limited rate).