Hi leb,
Once quarantined, files are locked away from your system and can't hurt it.
If all you are getting are tracking cookies (text files) and MRUs (Most Recently Used items), then you have nothing to worry about anyway. To control these, see my post in this Topic:
objects don't go awayIf anything else appears in your scan results, quarantine it - wait at least 2 -3 weeks, to ensure that it is not a critical part of your system or any program that you use.
After that, it is up to you when you delete the quarantined file.
That said, should you quarantine something (other than MRUs or Cookies) and it keeps re-appearing, you may have an infection. In that case, you should post back here in a new Topic, with a full description of what the problem appears to be.
Regards,
Spike