Any program which employs a Windows Hook DLL will cause Free cell and Solitaire to crash. In our product these tools are Error Tracker and Recovery Commander monitor. Microsoft has acknowledged that there's a problem with Free cell and Solitaire:

http://support.microsoft.com/?kbid=304402

If you want to run Solitaire and/or Free cell from MS, we can recommend stopping our two tasks. If you have other Windows Hook DLLs running from other applications or wish to leave those tasks running, we recommend downloading a non-Microsoft version of Free cell or Solitaire, e.g. from:

http://www.123freesolitaire.com/