chap MD5 & cisco

I'm getting a chap auth failure "wrong password" while attempting to 
auth against what the ISP tells me is a Cisco Access Server. (see ppp 
debug below)
I've verified the password etc. by testing this same connection with 
Windose, and I've looked and checked again my entry in chap-secrets. I'm 
able to auth against other ISPs using chap MD5, just not this one.

Any help would be greatly appreciated.

Mark

Feb 16 21:39:17 kws585g pppd[25444]: rcvd [LCP ConfAck id=0x1 <mru 1524> 
<asyncmap 0x0> <magic 0x2354cb2d> <pcomp> <accomp>]
Feb 16 21:39:18 kws585g pppd[25444]: rcvd [CHAP Challenge id=0x1b 
<08172edd83c1d8cc3672f106dfe14441>, name = "VPN-0"]
Feb 16 21:39:18 kws585g pppd[25444]: Warning - secret file 
/etc/ppp/chap-secrets has world and/or group access
Feb 16 21:39:18 kws585g pppd[25444]: No CHAP secret found for 
authenticating us to VPN-0
Feb 16 21:39:18 kws585g pppd[25444]: sent [CHAP Response id=0x1b 
<a4ceba1cf218900b223dddb967917dd6>, name = "<myusername>"]
Feb 16 21:39:20 kws585g pppd[25444]: rcvd [CHAP Failure id=0x1b 
"Reason::0202::Authentication Failure - wrong password."]
Feb 16 21:39:20 kws585g pppd[25444]: Remote message: 
Reason::0202::Authentication Failure - wrong password.
Feb 16 21:39:20 kws585g pppd[25444]: CHAP authentication failed
Feb 16 21:39:20 kws585g pppd[25444]: sent [LCP TermReq id=0x2 "Failed to 
authenticate ourselves to peer"]