Gshaughn - 2:50 pm on May 2, 2011 (gmt 0)

Friday one of my sites suffered drops site wide, all pages, all kws....here are some examples.
#16 to #45
#7 to #68
#5 to #44
#6 to #59

All of my other sites are fine. One thing I noticed in wbmstr tools was my site performance page speed dropped to 4.9 seconds from 3.x previously, and was updated 4/30 (saturday).

Notes:
-affecting entire domain negatively, but no 'set' ranking drop (ex. minus 950, minus 30) that might be indicative of a penalty
-other sites I own with the same newly added back links not affected (could be a matter of time)
-other sites I own with same monetization model (affiliate) not affected (could be a matter of time)
-#16 to #45 is a lesser drop, comparatively, to the others, but the most competitive kw phrase. Could this ranking be 'propped up' because we have more positive seo factors where as the other terms may be affected more severely by a single factor, such as, slow page load time?

Has anyone experienced anything similar? Any ideas or things I should be looking at?

Thanks,
Greg