SPA3000, PSTN Voltage and Impedance

[desistud]

Hi,
I am trying to configure remote SPA3000 and have it registered to my Trixbox. But I am seeing a wide variation in the line voltage levels. On hook state it varies between -44 to -51 and off hook it goes to 127 (ouch!). These are the readings that Sipura Info tab reports. If I put a phone on that line (pull the line from SPA and put a phone) it works fine. But when I put it in SPA the status is Ringing and not Idle.
Questions:
1. How reliable are these readings. I have a SPA3000 here with me and it has a very stable voltage so I feel they are pretty reliable.
2. Has anyone ever seen such variations or they are way off mark and something else is going on.
3. This phone line also has DSL connection on it and I am putting the splitter phone output to SPA3000. Is it possible that the splitter is bad and some leakage is happening while surfing on the net which is causing this fluctuations.
Any suggestions?

[desistud]

False Alarm. The cable I was using was flaky and after 2-3 phone calls I could see the dialtone fading in and out...changed the cable and problem fixed. :-)