cas: IB doesn't allow active orders to be routed to ARCA or REDI, you only can route passive orders there
Dave: You were not the only one who tried to convince IB management not to disable active routing to ARCA and REDI, I wrote them many e-mails, too
Also, what was worst, they didn't tell anyone about the changes (at least I was not told) and I remember, I spent like 2 weeks trying to find out what was wrong with my orders, I spent hours on the phone, e-mailing customer service, nobody could tell me why my orders to ARCA and REDI were beeing cancelled (they made me re-install the TWS, the Java plug-in, they made me monitor all my trades, etc. and send them the results...) (fyi I usually use market orders, so all of my orders were beeing rejected)
After 2 weeks, I was told IB disabled the active order routing and hence my market orders were beeing cancelled; the reason I was told, was that IB customer's orders were crossing/locking the market;
As for Primex, I also don't like the delay caused by the order going first to Primex, since 99% of my orders don't get filled there anyway. (trade Nasdaq stocks only)