Some time a particular freq. range doesn't work for you, consider changing to some other range. If you look at the OC profile you selected(starving in this example, and provided that you're using titan's power kernel), you can find a list of selectable freq.: Code: FREQS="0:22,90 125:22,90 250:28,180 500:29,360 550:32,400 600:34,430 700:41,430 750:42,430 805:45,430 850:46,500 900:49,500 950:52,500 1000:55,500 1100:63,520 1150:69,520" Say if the max. freq. 850 caused problem on your N900, you may step up or down, say 805 or 900, to see if the same thing would happen again. Similar case for min. freq., though I usually set it to 500 for OC. In my case, 500-950 is more stable than 500-850. YMMV. Load up OC profile only when need(to save your battery, to make phone app more stable, etc.). You may setup Queen's Becon Widget to load/unload OC profile on desktop. Hope this help.
FREQS="0:22,90 125:22,90 250:28,180 500:29,360 550:32,400 600:34,430 700:41,430 750:42,430 805:45,430 850:46,500 900:49,500 950:52,500 1000:55,500 1100:63,520 1150:69,520"