That's why i could not get any work.... you have it all (and a very very big disk ;>)

Seriously, i think something similar was reported for beta testing jobs, so what project is this for and what are the version numbers showing in the Tasks Tab of the BOINC mgr (Advanced View)?

Your client we presumed to be 5.10.45? A few early 5.10 and 5.8 versions did multiple switches when in deadline trouble.

Does the pausing switch to the waiting job i.e. does it eventually run? With a million jobs, they must be running in high priority (Tasks tab of BOINCmgr, last column) at which time the client tests to check which has the earliest deadline and does those first and pauses anything due later.

If in High Priority is that right from the start of the client?

If you look in the advanced menu, preferences screen, what is the connect value e.g. 0.3 and what is the additional buffer e.g. 1.00 (network tab). How many Processors are listed (Processor tab). The default is 16 so change this to 2. Maybe somehow BOINC thinks its a Hyperthreaded CPU, though it's not.

Also if you open up the Message Tab and select a good range of log entries that shows the switching, hit the copy selected messages button and post them here we can read.

Probably a project reset is required or further system info, but lets first hear on the findings.