Not for me, and afaict, it has never happened to me before. Except … when at some point you have run ./first-update or context --make as superuser, then the files from that run will be owned by the superuser from then on. My guess is that some of the files inside your local context tree are no longer owned by you.
I probably did that long ago.
You could wipe the install (as superuser) and retry. Or, if you are familiar with unix file handling, you could (as superuser) reassign the affected files to your own user account from within Terminal, like this
First, check the output of this:
$ sudo find <contextinstallroot> -not -user <youraccount>
Then run:
$ sudo find <contextinstallroot> -not -user <youraccount> -exec chown <youraccount> \{\} \;
Thanks, I learned a couple of new tricks. Cheers, Jörg