Using MS Forefront TMG, we tried to have FogBugz available internally with a path (say http:/server:123/fogbugz/) but externally without a path (like http://support.ourdomain.us/). That caused some cookies to use / and others to use /fogbugz as their paths...
Fog Creek support (their case FC2334884) had us add a special (undocumented) registry key which solved both logging in and the lacking arrows:
[HKEY_LOCAL_MACHINE\SOFTWARE\Fog Creek Software\FogBugz\website]
Aside: don't add this key from a 32 bit program (we used a 32 bit file manager :-< ) if your FogBugz runs as a 64 bit process. It will incorrectly use KEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Fog Creek Software instead.