charterm event not ready when bytes are available

[b2coutts]

I have constructed a small program which causes the (current-charterm) event not to be ready for synchronization, even while (charterm-byte-ready?) produces #t. The behaviour seems to somehow be linked to calling (charterm-screen-size). It can be induced by running my program and mashing keys as fast as possible (see also the comment block at the beginning of the program).