CLI hack problem

["rectorydp" <dpullen@xxxxxxxxxxxxxxxx>]

Hi

I need a bit of help and I know this list is my best bet and it is
even on topic. I have hacked one of the cheap BT caller display
units as used here http://tinyurl.com/exy4z by Dean Smith
(the blue
and yellow unit). I used roughly the same circuit as James Derrick
(see here http://tinyurl.com/bto9s). However, I
used a different
opto-isolator (SFH618-A4) from Rapid Electronics (see
http://tinyurl.com/93l6u).

Everything seems fine but when I receive a call the first part of the
serial data is picked up in hyperterminal and then, just over half way
through the caller number, the transmission appears to stop, ie I get

UUUUUUUUUUUUUUUUUUUUUUUUUUUUU=D5=80 112802042=20
01234-5=20

There are still another 5 digits of the calling number to go plus the
rest of the data. The same thing appears to happen for every call.

I am really not sure what could be causing this problem. The full CLI
is shown on the lcd display so everything still seems to be working in
the caller display unit. Unfortunately I don't have any test equipment
other than a multimeter which isn't much help here!

Any thoughts....please..

Thanks
David