buffer~ can't resize now

Greetings,

I'm having a problem with [buffer~] objects. As soon as a [record~] object is associated with a [buffer~], I can no longer resize it. Setting the [record~] to a different name doesn't help, nor does clearing the buffer. I don't care for the contents, I just want to erase it, set a new duration, and then record again.

Simple to test: use the [record~] help file and try to change the buffer's duration. Even deleting the [record~] object doesn't work...

BTW cropping doesn't work, neither does replace etc, they all produce the message "buffer~ * can't resize now" (or ...read file... etc). I'm on Max 7.

What I'm trying to do is use it in a phase vocoder, where I'd store the spectral representations to disk for another patch to use. If I put in a random largish size, I can do all that, but I'm wasting disk space. So what I want to do is to have the [info~] object report the file's duration (outside the [pfft~]), and send that message inside the spectral patch, do some arithmetic with the vector & hop sizes etc (that part is correct, I checked), and use that number to resize the [buffer~] before I record anything. Then I'd just trigger playback and recording at the same time.

Solutions? Workarounds?