font problems with new TEX installation

[Steve.Esson at esa.int]

I've installed a new version of Tex on the systems here for
the first time in about 10 years.   Documents which previously
processed OK, now produce errors like this:-)

! Font OT1/cmr/m/n/10.95=cmr10 at 10.95pt not loadable:
Metric (TFM) file not found.

  What does this mean? I'm an amateur at this and there
doesn't seem to be enough info around to find what the
real problem is.  The TEX directory, for example, contains
a file called "cmr10.tfm", which is identical to the file of the
same name in the old TEX installation which works.

  Anybody any idea what I should be doing next to
sort this out?

  Thanks,
S.