Sluggish Start with "Not Responding"

Sometimes DT opens quite slowly (5 minutes), with the process showing up in red as “not responding” in activity monitor. Eventually, I may get a warning about the data base already being in use, so I click on continue and DT finally comes up. This is before specifying the database. When I do select a database, I get a message that DT either wasn’t closed properly or there is another version of DT trying to open the database (not true). I click continue; DT again “goes red” in Activity Monitor as the database slowly reads in (it’s about 3-4 GB in size, about 24M words total). Eventually, it completes (5 minutes?).

Is any of this normal? Ideas?

The primary potential culprit, if there is one unique to my machine, is the virus checker (McAfee).

Concurrent filesystem activity (e.g. virus scan or Time Machine) might indeed slow things down a lot.

Problem turns out not to have been virus checking. Restarting resolved the problem. The odd thing, however, is that I had previously restarted without the salutary results. Perhaps OS X doesn’t always clean itself up fully in a single restart.???