OS "hiccups"

[Smith, Herb]

All,

I'm running Fedora 10 and have been very happy with it.  Within the last
week, however, the OS seems to be experiencing momentary "hangups" of
some sort where all activity stops for 10 or 15 seconds.  The cursor
won't move, web pages won't scroll, etc.  This occurs not only in
Firefox, but generally regardless of what I'm doing. 

Does anyone have any idea what could be causing this?

TIA,

Herb