You need to install all the patches. There were many serious
bugs fixed in 7.01 and 7.02. There is also a 7.03 out now, which
wouldn't hurt to install either. I believe you'll need to install
all three patches in order. You can find information about the
patches and bugs on
Peter Grainge's site.
I don't think the projects you've opened with 7.00 will be
fixed automatically by these patches, but any new projects, or ones
you haven't yet upgraded won't show these issue. For the effected
projects, if you haven't done anything apart from upgrade them, you
could restart with backup copies, but that might not be a
possibility if you've made a lot of changes.
I'm sure Rick, Peter et al. will jump in with additional
info, but you can at least have a look at what Peter has already
put together.