Error "Attempted to read or write protected memory"

i keep getting this error on my ASP .NET 3.5, this error did not appear before on our old hosting company, it was running on win 2003 and iis6

here is the complete error

Exception information:
Exception type: System.AccessViolationException
Exception message: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

 

It may be related to SP1. Please create a ticket via the control panel regarding this matter.