funny foam issue??

riddle me this ladies and gentlemen, recently (the last two kegs I've tapped) I've been having foam issues. Keep in mind nothing has changed in the three years that I have owned my current house. Every pour starts like normal. then about three seconds into the pour I get a burst of foam. I push my beer fairly slow (at about 5 psi) and have never had anything like this. this is happening on every glass. three seconds good then a big burst of foam. turn up the gas a little, same thing. Turn off the gas, same thing. Purge the keg a little, same thing. what's up with this? the only way I can get good pours is to fill a pitcher wait two minutes and then pour glasses...

frustrating to say the least. anybody ever experienced anything like this?

sounds like the beer is foaming up in the lines...

If you pour two beers back to back, I bet it doesnt foam up does it?

you know, now that you mention that I realize my first post wasn't entirely correct I did replace some lines recently. If the beer lines are longer or of larger ID this could happen couldn't it? Thanks sirsloop, you got me thinking. now to go check my lines...