context_get is disabled when the script stops executing, so this is normal.
Edit: Have you set up any mappings? It doesn't look like it, but I like to be sure.
Try exiting, deleting the .vpwhistu file and trying again. You'll have to set breakpoints again. Keep it simple.
Try a clean config.
If none of that is elucidating, then please send me an example project that reproduces the problem along with steps to reproduce (e.g. where to set the breakpoint etc.). Thanks.
++rodney