Hello! When plugging an external display in the mini display port, the internet speed decreases significantly. Not such of a big issue, but strange and unexpected behaviors are always annoying. I'm explaining my problem in details, but first let me apologize for bad English and/or lack of accurate technical terminology. Well, I have a MacBook Pro, connected via Airport to the router and by taking internet bandwidth tests (using the Speedtest.net), I've noticed large variations in speed performance (i.e. from around 20Mbps down to less than 1Mbps DL speed). Apart of the tests, the bad correspondence is obvious by using internet and further the WLAN (I have also attached an external HDD on the router). I live here for a short time, but I took the tests at different times during the day and for several days, since I'm unaware of how the ISP traffic might influence the speed and performance. I have restarted the router many times, which is located in the same room with the computer and functions under the 802.11g protocol (no firmware update have been found). I most of the times have plugged different stuff in the computer, like the external monitor, wireless keyboard, mouse, but recently i unplugged everything and tried a speed test next to the router. The speed reached the peak, so I moved the computer back to my desk, and the test scored similarly high-speed results. So in this case, I secured that the distance was not playing important role, as expected i guess, within a small room at a distance of 3-4 meters from the however low-class router. When starting to plug in the peripherals again, I noticed that, when connecting the external display and only then, the speed falls significantly (to around 1Mbps). Removing it, performing the speed test (speedtest.net again) and the results go high again (to around 15Mpbs). So, there they stop my observations. One of my assumptions is that power used to feed the signal for the external monitor affects the power that the wifi antenna is using (like as the computer was moved far from the router. However, the connectivity indicator still displays excellent communication with the router.) Is it this a silly idea? Or could it be any frequencies interference? I don't hope to a solution so much (due to the bizarreness of the case), but I would be glad for your opinions, ideas, suggestions, even reproduction of the issue. By the little I've searched, I haven't found a related thread, but I'd be happy, in case someone can lead me there. Finally, i'm sorry for the text's length, but I wanted to describe the situation as precisely as possibly I can think of. Cheers!