Closed Transaction Keeps Running...awaiting Command

I am debugging an app which blocks many processes in a SQL7 server DB.
The app log writes every transaction "open" and "close".
The weird thing is : when the app logfile says the transaction is
dropped (object closed) the db keeps showing the process "running", in
a sleeping mode, with open_tran in 2 or even 3 and in an awaiting
command status.

We are working on NT4.0, SP6a (all fixes up to date, MDAC 2.7SP1) on
IIS side, an equal box for MTS (same patches and updates) and a SQL
Server 7 (on NT4, same fixes ans SPs) database on another box.

Is this normal? Those sleeping processes are blocking other apps and
everything gets slow and messy....the only solution is to kill those
blocking processes.

Thanks!