Lenz 90 problem

I have a problem with my lenz 90 system stack. I cannot enter the number 0003 to drive new locos with that number on the chip. I know it was there when I bought it but I seem to have stuffed it up somehow. I have followed the instructions in the manual precisely and exactly on several occasions to no avail.

I have in the stack in order

0053 which drives that loco

00.86 which drives that loco but why the full stop in it ?

0.0'0.3. which does not drive a decoder with 3 on it

00.93 which I was trying to set up

0.0'0.3. again

00.04

00:91 which drives a loco, but why the colon ?

0.0'0.3. again which was where i was trying to enter 0003 again.

Please can anyone enlighten me as to what i have got wrong ? Also the meaning of these various dots, if any, would be useful.

I would be grateful for any advice on this problem.

Andrew