We have build an sql-server 7 application with an acces 97 front-end and we experience extreme blocking in the database. When the acces application runs an sql statement (update, insert or sp) the locks on the effected objects (tables) are not released. You have to manualy clean the system by killing spids.
It is very strange that some computers don't generate these blocks. These computers can run the same sql statements on the server without problems. I think this looks like an odbc problem. When we install an odbc package the computers runs perfect. But after a while the computers get corrupted and generate blocks in the database.