ILS DME strength?

Does anybody know the typical range of the DME signal when DME is installed
in conjunction with a localizer or ILS?

I shot an ILS yesterday that had it's compass locator decommissioned some
time ago, so now the approach requires a VOR or DME, which is fine, because
we've got both in addition to the GPS. But the DME seemed to act pretty
flakey. Sometimes it indicated over one hundred DME out, when we were only
8-9 miles away. Outbound it flickered on and off, inbound it was dead on
perfect. It also worked perfect flying back to our home airport that has a
VOR/DME on the field.

Is the DME associated with an ILS a "low power" or special version that is
different from that installed in conjunction with VOR's?

Thanks,

Jim