Software loading problems

Avast Free Antivirus / Premium Security
1

Hi,
I work for a long time with Microsoft Flight Simulator and Avast pro 4.7 on the xp64bit platform. Lately, about 2 months, my computer can’t lunch a flight in the simulator. I search and found that if I turn off the next list of software in the “Standart Shield” control the problems stops and the simulator work regulary.

  1. “Scan OLE documents on open”
  2. “Scan executed programs”
    -“32-bit\64-bit windows…”
    -“16-bit windows…”
    -“Ms-Dos based…”
  3. “Scan dynamic libraries”

Is somebody know any way to solve this problem?
Is it possible to work without these software?

thanks for help, Amots.