RF remote control using VirtualWire on ATtiny85 running at 8MHz on internal oscillator
I tried those Tiny cores you are using and had a lot of problems. I switched to http://code.google.com/p/arduino-tiny/ and it seems much better. Create a second Arduino installation folder and add the arduino-tiny cores.  The pin name constants are like PIN_A0, PIN_A1,...,PIN_B1, etc. So, try that out.

I looked briefly at the VirtualWire code and there are ifdefs specifically for the Attiny85, so it should work.  Here is a derivative project with working ATTINY85 examples: http://cosa-arduino.blogspot.de/2013/03/news-virtual-wire-interface.html