I figured i'd contribute with some of the top issues regarding the use of DTV converter boxes and reception based on my experiences, which were far from successful until recently.
TOP CONVERTER BOX PROBLEMS:
Remote stops working, or only works on some functions and not all.
If the channels don't change, most likely it's from using the up/down arrows instead of the actual channel up/down button. on some satellite receivers, it doesn't matter but on most DTV converters it won't change channels by using the arrow buttons. the box can be 'confused' and resetting to factory through the menu, unplugging the box, replacing the batteries in the remote, and then plugging the box back in, and reinsert the remote's batteries can solve a problem such as that. usually it's a confused electronic state that can also cause the box to get 'frozen' or stop responding to the remote entirely.
Converter Box loses reception, but reception does not return, after wind, rain, or snow.
Box has possibly gotten into an extended state where the signal was nonexistant or in the 'red zone' of the signal meter and after a few seconds some boxes do what i call an 'unrecoverable signal drop' and refuse to lock the channel in question or even so much as forget the channel if you scan up/down to find ones with signal and return. usually you have to simply turn the box off, wait 5-10 seconds and turn it back on. this will force the box to attempt to aquire the channel again. usually this works if the condition that caused the error is over. it's also important that some boxes won't do as well when set up during bad weather, they seem to use the signal they get when scanning the first time as an average so it stays near or on that percentage. so re-scanning (not easy add or update scans) from scratch during optimal conditons will help alleviate this problem in the future.
Signal drifts back and forth from good to zero (no signal) off/on or when viewing signal meter, picture constantly has pixellations and loses audio stream (Cliff Effect)
Check antenna wires, or connections, this is sometimes caused by the smallest of connections or bad cable even if it seems to be ok. it also can be the weather having a similar effect on the reception as it would on Satellite TV reception (rain/snow/weather fade) even though there is no satellite signal the same issue can be done by the weather when it was normally not an issue with analog reception. you may just have to wait for the condition to clear.
Program Guide is missing, incorrect, or time/date is wrong.
You may not be getting an update from your local station, or it doesn't support it, or you have the wrong time zone selected during initial setup. sometimes however, the program guides either don't exist for awhile, or they are 'off' such as times when the station pre-empts it with sports or paid-advertising. try verifying the time settings and zone and any Daylight savings time settings are correct.
Converter box shuts down
The Converter Boxes are Energy Star compliant. this means they are pre-set to turn themselves off after a certain preset time. (usually an hour or two) you can change the time delay or even disable it entirely in the menu (under OPTIONS or ETC or SETTINGS, usually)