On Vista 32, I upgraded ESS from 669 to 672. Normally I do a clean install but this time was in place. Previously used Wake On Lan (WOL) from Depicus many times and the rules from 669 were still present. During a normal day with plenty of different applications open, I started WOL and clicked the Wake Me Up button and received a BSOD. After reboot, I tried WOL again and got the BSOD again. After reboot, I disabled the ESS firewall - just a feeling I had - and WOL worked fine. With WOL still open, I re-enabled the ESS firewall, clicked the Wake Me Up button and received two WOL outbound prompts for which I created custom rules. WOL worked perfectly. I closed WOL, reopened it and clicked Wake Me Up and got a BSOD. Uninstalled ESS and WOL worked fine. I rebooted, WOL worked fine, cleaned folders and registry, rebooted and WOL worked fine. I reinstalled ESS, rebooted, trained the firewall, and WOL caused a BSOD. Reverted back to ESS V3.0.669 and WOL once again works perfectly. In all fairness, I do run Microsoft's Firewall Client (FWC) for ISA Server 2004 and, according to this thread, there are issues but these have never been formally acknowledged and ESS normally runs OK alongside FWC.