I am experiencing a similar problem, right after updating to Version 1.8.0.24401, 64 bit on a Windows 8.0 64 bit machine.
When trying to connect to an existing repository i am getting the following error. In file 'D:\Development\SVN\Releases\TortoiseSVN- 1.8.0\ext\subversion\subversion\libsvn_client\ra.c' line 647: assertion failed (peg_revnum != SVN_INVALID_REVNUM) --------------------------- OK --------------------------- Any ideas? Thank you in advance for your support, Günther