Peter,

Peter wrote:
That worked fine until i got my US ASEL rating, at which point the
temporary US Glider private rating was no longer valid and I had to go

I was digging web, and found an official document addressing this
specific issue.
http://www.faa.gov/library/manuals/e.../8700/volume2/...

Here is an excerpt.
NOTE: A person who applies for a U.S. pilot certificate by
accomplishing the appropriate pilot certification requirements of part
61 and also holds a pilot certificate issued under 61.75 need not
surrender that U.S. pilot certificate. There have been isolated
incidences where examiners have erroneously required a person to
surrender the 61.75 pilot certificate when applying for the standard
U.S. pilot certificate. In this instance, it is permissible for a
person to hold both a pilot certificate issued under 61.75 and a
standard U.S. pilot certificate.

Your glider license should have been valid.

-Gen