(I'm still running core 6)
I have the same monitor. I used to have a problem on boot, but that was before I got the proper drivers for my (on-mobo) graphics chip. My problem may have been different. It involved the X-server not being able to recognize the Acer AL1706. I went into the diagnosis as root and found that AL1706 was not listed among the monitors, but that generic LCD worked fine.
I see to remember using it at the frequency and resolution you mentioned.
Using the correct drivers now (nVidia, in my case), the system has set itself to 1024x768 at 50 Hz. It looks fabulous, but now I have trouble changing to lower resoultion modes.