Never try to close a VC round during the summer.
The problem is magnified if you're using a syndicate of several firms. The timing issues are a nightmare. Your VC will go on vacation (times however many VC firms are in the deal). Your lawyer will go on vacation. The VC's lawyers will go on vacation. Things that should take days, take weeks instead.
I'll be making a number of posts over the next few weeks detailing how we put together a VC investment.