pushpool not updating mysql
First of all I thought that you were using a bitcoin pushpool as your primary software for a litecoin pool. But I guess you've checked that?
Otherwise, try this recomended pushpool fork instead, which worked for me: (For LTC) https://github.com/ArtForz/pushpool

This one works for me, but ideally you would want to use the stratum software for mining purpose. (If you have clients connecting with LP/Getwork, you can add the stratum-proxy locally on your server)