It sounds like something is interfering with the download such as antivirus/antispyware/firewall software. Try adding an exception for Impulse.exe to this kind of software if you have any installed. If this does not help, try temporarily disabling this type of software and then try again. Be sure to re-enable after you have tried Impulse. SpyBot and Ad-Aware are especially troublesome with Impulse.
Ebonawit, I do not see a support ticket under your email address. Do you have any support ticket ID numbers?