That probably explains LOTs about these exclamations and the dramas (for Toppy owners). The Toppy feeds back that it has particular timers set for a particular time to ICE, and maybe when the times are not the same times as ICE is expecting (i.e. right on the hour/30 min mark) ICE thinks the timer didn't get set and brings up the exclamation.
You should ALL hassle Topfield to get rid of all dependence on the broadcaster when you are set to manual time. It is ridiculous they still use the timestamps for some parts of the unit operation, the idea of running manual time is to 100% remove that dependence.
Not only this, but because the timer start times are dependant on this "moving window" between delta's of different broadcasters and your front panel clock, there is the potential when ICE says "set a timer for 1000 GMT" and the PVR adds its dodgily created GMT offset, lets say 10hours and 2minutes (because, say, Nine time of day GMT timestamp is 1minute different offset to ABC for example), while other timers already existing in the reservations have 3minute offset, you will have unnecessary clashes and possible rejections for what are meant to be adjacent timeslots, and/or 3 way overlaps which the unit will likely reject also.
So continuing that example above: 1000GMT+10hours2mins=20:02HR=8:02pm... but say some other timers show something starting at 7:03PM with a 1hour duration... bang, you get a clash, some finishing at 8:03PM while the new one you want to create is starting at 8:02PM (lets say that you added this show later in the week than the others, or ICE took a while to realise the proper timeslot of that particular show... there is all sorts of reasons why the timers aren't necessarily all created at the same time for the same day). All because at any one time, your offset could be a minute or a couple or more different due to your front panel clock drift, your seconds being different to the broadcaster seconds, and broadcaster subtle clock variations between each other (and not so subtle for some of the regionals where they set the clock to localtime instead of GMT by accident/negligence and so suddenly your box is 10 or 11hours behind for timers/EPG!)
5K owners would have hassled them, but various timer taps work around this anyway, and Topfield probably aren't interested in anything further with those old models.