Cannot dial any number that contains the string 089

Yes it’s odd. I have 8 setup as a prefix in my outbound route.
Example number: 819089999999

As soon as i dial 819089 it stops listening to key presses and starts the call

Further research 815129089 gives the same problem right after the 089

Any ideas why that string would kick something off?

Here is the log output from asterisk when dialing:

  == Using SIP RTP TOS bits 184
  == Using SIP RTP CoS mark 5
    -- Executing [819089@from-internal:1] ResetCDR("SIP/5329-0000026a", "") in new stack
    -- Executing [819089@from-internal:2] NoCDR("SIP/5329-0000026a", "") in new stack
    -- Executing [819089@from-internal:3] Progress("SIP/5329-0000026a", "") in new stack
    -- Executing [819089@from-internal:4] Wait("SIP/5329-0000026a", "1") in new stack
    -- Executing [819089@from-internal:5] Progress("SIP/5329-0000026a", "") in new stack
    -- Executing [819089@from-internal:6] Playback("SIP/5329-0000026a", "silence/1&cannot-complete-as-dialed&check-number-dial-again,noanswer") in new stack
    -- <SIP/5329-0000026a> Playing 'silence/1.ulaw' (language 'en')
    -- <SIP/5329-0000026a> Playing 'cannot-complete-as-dialed.ulaw' (language 'en')
    -- <SIP/5329-0000026a> Playing 'check-number-dial-again.ulaw' (language 'en')
    -- Executing [819089@from-internal:7] Wait("SIP/5329-0000026a", "1") in new stack
    -- Executing [819089@from-internal:8] Congestion("SIP/5329-0000026a", "20") in new stack
[2012-01-27 14:20:06] WARNING[2951]: channel.c:4641 ast_prod: Prodding channel 'SIP/5329-0000026a' failed
  == Spawn extension (from-internal, 819089, 8) exited non-zero on 'SIP/5329-0000026a'
    -- Executing [h@from-internal:1] Hangup("SIP/5329-0000026a", "") in new stack
  == Spawn extension (from-internal, h, 1) exited non-zero on 'SIP/5329-0000026a'

What brand of phones? Check the digit map on the phones.