[p4] Files(s) couldn't be locked error

[Mike]

When I try to do a rather large submit on to my remote Perforce server, 
P4v gives me the error:

"p4 submit -i
File(s) couldn't be locked.
Submit failed -- fix problems above and then us 'p4 submit -c 65'"

p4v never gives any list of files that it can't lock. It only gives this 
one error message.

Does anyone know what causes this, and how to fix it?

I am using p4v on an Intel Mac mini with a 10.4.10 configuration.

Thanks,

Mike