Belt clip
Typical question: "the user manual describes a belt clip, but I couldn't find it when I bought my phone. My dealer says they have never been included, is this true ?". Yes and no. The chance to find a belt clip in your T28 box is vitually zero. Only very early models included this clip, but it was found to be unreliable and people lost their phones while it was hanging, so Ericsson ceased the production. The Ericsson ImageWare holster might be a valuable alternative for you if you need to hang your T28 to your belt.  

Flip
People who are considering the purchase of a T28 are often very concerned about the problem of the flip : "what about problems with the flip which seems to be very fragile ?". It seems that the first releases of the T28, specially those manufactured in Malaysia (today, most of them are made in Sweden) experienced a couple of problems with the flip which broke easily. Things are improving today, even though you might have some problems with it (I had mine replaced for free on a 4-months old T28 which opened without pushing the button, just pulling the flip down). Some people pretend they increase the flip's life duration by pushing the release button to close the flip.
In relationship with the flip, don't forget that the service menu of the latest T28s allows you to see how many times you've opened your flip. 

Charging advice
A very common issue on the T28 world, almost unknown (as far as I'm aware of) on the T28s, is related with power management. The "Ericsson charging" message pops up frequently and without reason on these phones. This rapidly becomes uncredibly boring. Says Michaël F.: "you cannot really play Tetris because you will be interrupted by a dialog box at regular intervals with the silly charging message; this will start once your battery (the LiPo model) goes down under 1/3. A most annoying behaviour [...] is the clicking sound that comes on at the same time. Since the backlight also comes on at the same time, this also wastes energy". Our advice would be to have your T28 replaced or repaired if you experience this problem. We don't have any clue about the relation between this problem and the next one.

Charging accumulator
So you were quietly using your phone, then it suddently powered off, and there was no way to power it on again. You're not the only one. It's a charge accumulator problem (it's not related with the charger itself), and it seems it's (too) common on certain series of phones. There are not thousand of ways to solve the problem: go and have it repaired: mine was replaced after this problem. 

Slow menus
Contrarily to a widespread belief, even the latest versions of the software of the T28 do not change the slowness of the menus when scrolling them down or writing a SMS. 

Microphone wire
The wire connecting the microphone on the flip and the rest of the phone is quite fragile and it is a known problem that this wire disconnects and/or breaks so that your phone can be used for reception only ...