So it's been a while, but I'm still having this problem... any time I leave bfxdata open for very long it eventually (sometimes actually quite quickly) locks up my browser for a moment before I'm asked to kill the script. When I do so it typically stays locked for another few seconds before asking me again to kill the script and then after that comes back to responding normally. If I then leave the page open the process repeats a few minutes later.

Slightly different error message though - "A script on this page may be busy, or it may have stopped responding. You can stop the script now, open the script in the debugger, or let the script continue. Script: https://ajax.googleapis.com/aj…bs/jquery/1.11.1/jquery.min.js:2 -- [Continue, Debug Script, Stop script]"