A re-ranking. First and foremost the system lockup problem: If you run iPulse on a laptop and use iDisk or other servers, you will find that iPulse will habitually lock your Mac forcing you to control-command-power hard reboot to get free.
iPulse will check the mounted volumes (hard drives) including remote server volumes periodically to update the usage status. When it does this and the volume is no longer available, it will not time out nor release the query call for disk usage statistics.
Here is the scenario: You are at work and you have a server mounted. Maybe it is your Windows NT corp server, Mac OS X corp server, your iDisk cloud server, or your TimeCapsule volume. You close the lid to sleep the Mac and it sleeps. Pack it in your bag, jet for the door. You then later open your Mac (on the train, at home, etc.) and you have no network connection or a different network connection that does not allow you to get to one of the servers that you were connected to before. iPulse will go brute force against that server asking for statistics and not let go. That server volume appears busy and the Finder cannot let go either. You establish an Internet connection (wifi, ethernet, cell modem, etc) and now nothing seems to be able to talk to the network even though you do have a connection as verified by the Network Preferences in your System Preferences. Then you check your process list (command-option-escape) and note that iPulse is not responding. You figure, ok, just kill it but that thing is a vampire and drains your network connection dry and cannot be killed. Kill Kill Kill, nope nope nope. Then you see your Finder go non-responsive. Kill, nope. Other processes, as they access network resources start to go red including iChat, Pages (oops, update check...) and others. Some kill, some do not. You try launching network utilities that just seem to bounce indefinitely (they are trying to open network connections and the network stack is gridlocked by iPulse, sorry charlie)
Ok, long story short, your Mac is Tango Uniform, time for the three key salute: command-control-power. This time you take iPulse **out** of your login items and come and write a lengthy review about one of your favorite little utilities becoming more pain that it is worth. Sad Monday, lost an old friend.