I had the same problem in my office for a while. Turned out it was the virus scanner keeping the db files open so svn couldn't access its own files anymore for too long. Convincing my boss to have that virus scanner removed from my machine and use another one fixed the problem for me.
-- You received this message because you are subscribed to the Google Groups "TortoiseSVN" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/tortoisesvn/e8c1d8c8-4147-4d8d-8b46-a44ccae2a677%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
