What is this alert??

["Marc Hering" <mhering () reval com>]

Hey All,
I keep getting this same alert over and over and over (About 5k times
already since Thursday)
 
(spp_stream4) possible EVASIVE RST detection    
 
I can't seem to find any usefull info on it aside from that it is
detecting a lot of RST requests...Is this a common alert that needs to
be tweaked or am I looking at something more sinister?
 
Thanks!
<M>