If you don't see anything in netstat other than the TCP Wait, I would guess there is only communication to check for new blocks and to submit a found block. In that case, presumably a found block would be cached if communication was interrupted, but I don't know if it would be quickly discarded the way a share is. Also, while I don't know, I would guess that something would indicate the communication problem when it became apparent to the miner (puddinpop's cuda miner will tell you communication is interrupted and continue mining and telling you it doesn't have communication). If it does, watching for that would make more sense than keeping track of rejected shares that don't benefit the server anyway. However, since communication isn't likely to be a miner problem, anything that might cuase a communication problem could probably be monitored elsewhere (monitor bitcoind or Internet connectivity or whatever you need for what you're doing).
who wants to go thru all that... a quick glance at cgminer humming allong showing rejected shares is alot easier...... How about a menu option for it?
. but what is 
