I had same problem until:
Changed browser (now firefox),
tried recolocating some directories,
and touched some gfg file in bin\proj\cm5ide.cfgx, of which now I keep a copy elsewher to avoid retouching each time a problem bursts.
I have observed that it grabs te btowser and makes other pages accessea slooow, so I don't use vry often thw web while i am working with that devil.
-M.A