Some menu's disappeared after upgrade to 3.4.2

I just updated to 3.4.2 and now it restricts the number of menu links I can have. It’s for a PR site so there is about a dozen top-level menu links, with each of those having 5 – 20 sub-menu links. After the upgrade it cuts it down to 8 top-level links. If I re-add them and hit save, they drop off after the page loads again. Any ideas? Thanks in advance.