<hot water and lemon>
I’ve been troubleshooting an existing PS2007 implementation recently (obviously not one that I set up!), and the customer was having problems with Qs entering the sleeping state (I know that feeling). This was only on their development environment, their live system was good to go.
The customer has tried all the usual tricks of rebooting servers, restarting services, checking SSPs for permissions etc. When we looked further into the issue we found that the SQL server (two server installation) was set at a different time from the application server. From memory it was out by an hour (daylight savings had not been implemented). Once the time was set correctly on the SQL server, everything worked fine.
I hadn’t seen this one before (I’ve seen the one with Analysis Services cubes not building because of time zone differences), so now that it’s coming up for DST time changes, check your time settings on your boxes.