Yes - there is no error created by having both iServers running - it's just that the HAH iServer can cause the Windows iServer to crash - (upgrade to the latest b12a version to avoid this).
The error is within the HAH version of iServer , and I think happens when it has a few successive messages to pass from xAPFlash - it seems to truncate some, possibly when they traverse a TCP boundary. Seeing more errors when xAPFlash sends larger volumes of traffic is inkeeping with what you're seeing.
There isn't a problem with xAPFlash or iServer Windows and I'm sure Brett will fix iServer HAH real soon. It's Thanksgiving holidays in the US , and this was his very first release so overall I think its pretty good.
K