The client was unable to reuse a session with SPID xx, which had been reset for connection pooling. The failure ID is 29

A couple of days ago we've moved a new site from staging to production to replace the old site. Since that moment every couple of hours SQL Server throws the error:

The client was unable to reuse a session with SPID 58, which had been reset for connection pooling. The failure ID is 29.

The w3wp service (IIS) throws 503: ser开发者_运维技巧vice unavailable and throwing it untill IISreset. Stressload of the server hasn't changed really and the DBA insists it's our (developer-team) problem because the old site didn't have any problems like this.

Reinstalling the system (or something like that) isn't really an option. The solution we've moved into production might be the flagship, but IIS serves a multitude of smaller sites and going offline for a longer period of time is out of the question.

Anyone experience something like this before? And how to tackle this?

TIA!