Not all text messages get sent from Droidx or Droidx2

Question

My family has stock Droid x and Droid x2s. We are using the Text App that comes with the phones. Both phones have this same problem.
Sporadically, text messages do not get sent.  They remain hung up, showing the green 'sending' arrow. None of the message goes out.
I have been able to identify the problem, but not reason, in one instance.
This message will not send. (dashes not included)
Page one
Jjhhbhhhvcfxdffggcccffg
gggvccffffffgggffgggggfffff
fggfffffffgggfffffffffffggggt
ggggggggggggttttttgtyyyy
ygyytyyyyyyyyyyttttttttt
tytttyyy
yyyyyyyt
Start page two¿
It appears that text in a message is broken up into 145 character chunks (probably for SMS limits).
Notation on my text app shows pages and characters left.( e.g. 145/1 for 145 characters
left, page 1 or 83/2 for 83 characters left on page 2)
1. I'm not sure that sending text from my phone via email did not add/subtract characters.
2. The 'P" in page one is the first character.
3. The 'S' in Start page two is the beginning of page 2
4. The '¿'  (an upside down question mark) at the very end of the text message is the problem.
If I replace it with any standard keyboard characters, the message gets sent.
If this  is located anywhere on the second page, the text won't send. Anywhere on the first
page, it sends OK.
The fact that this character (Hex 'bf', for those that care) can be sent on the first page smells
like a bug.
Thanks for listening to a blithering idiot!!

Answer 1

Thanks for your response!
To answer your questions:
No, yes, yes, no  . . . Just kidding!
Anyway, I had never used a third party app.  I just downloaded Handcent SMS
texting app.  It exhibited the same issue that the default app does.
The way the message behaves I'm sure it doesn't even get to the point of
trying to send the message. The sending arrow on the message stays with the
message forever, or till I delete it, and the  Handcent app shows its'
"sending" spinning gear on these messages forever.  Other successful
messages don't show these icons after the message is sent.
If I send a 'normal' message, the green arrow hangs around for a while and
then disappears once the message is sent.
I have tried to send this message to a friend who has an iphone and is on a
different carrier. It behaves the same, and does not leave my phone.
I have sent this message to myself from my wife's Droid X2 with the same
symptoms.
The failing text I sent you before was what I used to trouble shoot the
problem ( to narrow down the 'offending' character). Below is a copy of the
original message that fails. If you could cut and paste this into phones you
folks have, you could try to send it yourself!  Note the "¿"  around the OK.
======Message
Hi, Carol
I just ordered tickets for NCAA womans first and second rounds at Gampel.
I ordered two tickets for you folks. They are $30 each.Total would be $70,
including handling charge.
¿OK? I'm sure out will be !
Jim
======Message end
I was able to copy the message above, paste it to my desktop as a text file,
open it from my phone and copy the text, then send it in a text message.  It
didn't send.  when I remove the upsidedown question mark, it sends OK
Thanks for listening.
Jim
P.S.  My email joat is part of JOAT MON (jack of all trades, master of none)
   Have a great Turkey day!