Strange problem with directed pickup

I'm having a kind of bizzare problem with directed pickup in MTE 1.4. I don't think this is a Thirdlane or Asterisk problem, but wondered if anyone might now what's going on. We're using macro-tl-directed-call-pickup with a feature code of _*8. and invoking length of 2.

I have a pickup softkey defined on the phones as follows (not copying all of the config here, but it works for most tenants):


efk.efklist.3.mname="Pickup"
efk.efklist.3.status="1"
efk.efklist.3.label="Pickup"
efk.efklist.3.use.idle="1"
efk.efklist.3.use.active="0"
efk.efklist.3.use.alerting="0"
efk.efklist.3.use.dialtone="1"
efk.efklist.3.use.setup="1"
efk.efklist.3.action.string="*8"

On my phone if I press the Pickup button it asks me to Enter More Digits. I enter the extension of the ringing phone, and pick it up. If I watch the Asterisk console I don't see anything from the phone until I press Send after entering the extension of the ringing phone.

But, for one tenant when I press Pickup it immediately sends something to Asterisk, and I see this on the console:

-- Executing [*8@from-inside-DSL_Inc:1] Macro("SIP/300-DSL_Inc-09e3b6b8", "tl-set-variables2|from-inside-redir-DSL_Inc|DSL_Inc") in new stack
-- Executing [s@macro-tl-set-variables2:1] Set("SIP/300-DSL_Inc-09e3b6b8", "__tenant=DSL_Inc") in new stack
-- Executing [s@macro-tl-set-variables2:2] Set("SIP/300-DSL_Inc-09e3b6b8", "CDR(userfield)=DSL_Inc") in new stack
-- Executing [s@macro-tl-set-variables2:3] Set("SIP/300-DSL_Inc-09e3b6b8", "__FROM_INSIDE=1") in new stack
-- Executing [s@macro-tl-set-variables2:4] Set("SIP/300-DSL_Inc-09e3b6b8", "__MOH=default-DSL_Inc") in new stack
-- Executing [s@macro-tl-set-variables2:5] GotoIf("SIP/300-DSL_Inc-09e3b6b8", "1 ?setmoh") in new stack
-- Goto (macro-tl-set-variables2,s,7)
-- Executing [s@macro-tl-set-variables2:7] SetMusicOnHold("SIP/300-DSL_Inc-09e3b6b8", "default-DSL_Inc") in new stack
-- Executing [s@macro-tl-set-variables2:8] Goto("SIP/300-DSL_Inc-09e3b6b8", "from-inside-redir-DSL_Inc|*8|1") in new stack
-- Goto (from-inside-redir-DSL_Inc,*8,1)
== Channel 'SIP/300-DSL_Inc-09e3b6b8' jumping out of macro 'tl-set-variables2'
-- Executing [*8@from-inside-redir-DSL_Inc:1] Macro("SIP/300-DSL_Inc-09e3b6b8", "env-Intercom-Polycom|1") in new stack
-- Executing [s@macro-env-Intercom-Polycom:1] SIPAddHeader("SIP/300-DSL_Inc-09e3b6b8", "Alert-Info: Ring Answer") in new stack
-- Executing [s@macro-env-Intercom-Polycom:2] Dial("SIP/300-DSL_Inc-09e3b6b8", "SIP/8-DSL_Inc|20|rtTA(tl/beep)") in new stack
== Everyone is busy/congested at this time (1:0/0/1)
-- Executing [s@macro-env-Intercom-Polycom:3] Hangup("SIP/300-DSL_Inc-09e3b6b8", "") in new stack
== Spawn extension (from-inside-redir-DSL_Inc, *8, 1) exited non-zero on 'SIP/300-DSL_Inc-09e3b6b8'
-- Executing [h@from-inside-redir-DSL_Inc:1] Hangup("SIP/300-DSL_Inc-09e3b6b8", "") in new stack
== Spawn extension (from-inside-redir-DSL_Inc, h, 1) exited non-zero on 'SIP/300-DSL_Inc-09e3b6b8'


Both phones are using the same script, and I think the feature is set up the same on both phones.
The same thing happens whether I dial *8 or press the Pickup key.
The Polycom dial string is the same on both phones.
If the customer dials (onhook) *8100 he is able to pickup a call ringing on extension 100 (I think. Going to double check this in the morning).

Here's the really weird part. If I edit the {mac-address}-registration.cfg file on the phone that's not working and set it up to register on my tenant everything works. It doesn't work when it's registered on the other tenant. So, the config files are the same except for the SIP registration for the phone.

Any idea where I should look for this?