Doesn't help. The tools.avrdude.erase and tools.avrdude.bootloader entries from the IDE platform.txt file are used instead of the ones from the tiny file.
Other than that though all is well (maybe its because I have a different core? though there shouldn't be an issue with that from the IDEs point of view).
It's not a core issue. It's an IDE issue. 1.5.1 has bugs in how platform.txt is handled. There are also some fundamental problems with the way entries are defined in platform.txt.
Thank you for trying to help.