Controller list disappears

Not sure if this goes into this forum or the support one...

 

 

After upgrading my Firepasses to HF-603-4.3 many clients are reporting that the controller list in the F5 VPN Client is empty.

 

 

I know a quick resolution is to copy the file %USERPROFILE%\Application Data\F5 Networks\VPN\client.f5c from a working XP PC onto the broken one, but I wonder if anybody knows why this happens or how it can be prevented?

 

 

I have a case open with F5 but no resolution yet. Upgrading has been a MAJOR support burden after the last two HotFix releases...