Intel Graphics refresh rate drop and are inconsistent after sleep or hibernate

Systems with Intel HD graphics have inconsistent monitor refresh rates, lower refresh rates and poorer graphics performance after resuming from a 'sleep' or 'hibernate'.

To reproduce for systems with Intel HD graphics:

1. Make sure the monitor is set to its highest refresh rate (e.g. on Dell U2711 monitor, choose 60 Hz rather than 59 Hz;  or on a Dell Latitude E6320 laptop, choose a refresh rate of 60 Hz, not 40 Hz).
2. With a user logged in, either close laptop lid, or put the system into 'Sleep' or 'Hibernate'
3. Wake the system up again and log in
4. Check the Monitor refresh rate under the Intel "Graphics Properties" - the refresh rate has dropped from the higher setting to the lower setting and is now either 59 Hz or 40 Hz in the examples above.
5. Check the Monitor refresh rate under Windows Control panel -> Screen Resolution -> Advanced Settings -> Monitor -> Screen Refresh rate.  Here the original higher refresh rates are still being reported.  I.e. the refresh rates being reported by Windows vs. that reported by the Intel driver GUI are inconsistent after resume. See attached screen-shot.
6. Use windows desktop - the system is now slightly but noticeably more sluggish/lower graphics performance after resume.
7. In addition, after the screen goes in standby, the screen 'forgets' brightness and contrast settings set in the Intel Graphics Properties after waking up again (screen returns to brightness/contrast settings it had prior to setting them in the Intel Graphics Properties).

This issue occurs both for the built-in laptop monitor as well as an externally attached secondary monitor (connected over DisplayPort).

The issue also occurs on the monitor attached to a Desktop PC running Intel HD graphics.

Monitors on which the issue has been reproduced:

• Dell Latitude E6320 built in laptop screen
• Dell U2408WFP monitor (Display Port)
• Dell U2711 (Display Port)

This issue occurs both for 2nd and 3rd generation Core i7 HD graphics, from a Dell laptop, as well as from PC with Intel Motherboard (Z77).

All systems running Win 7 Pro, sp1, x64 with all updates, latest drivers and BIOS.

Thanks

EBL