writing a temp matrix to disk

hi there...

i have a patch that loads in a text-based matrix data file and temporarily writes it to disk (for archiving) via jit.matrix, then loads that jxf from the specified location.

i am loading it while i also have a JSUI that is pegging the CPU at low priority, quite nastily.

the problem i am experiencing is that if the JSUI is open (and sludging along), the jit.matrix can't seem to write the data file. i have no idea why this would be happening though.

i get the message:
jit.matrix: could not create file my/example/path/myfile.jxf
the path is correctly formatted and if i try the identical operation without the JSUI involved, it works fine.

i hate to issue questions like this with a preface that the patch is giant and not worth posting, but this seems to be the case. there are simply too many things going on and i know that the write operation should work... i've just never seen this behavior.

would anyone have any thoughts on what could be happening there?

thank you,
jml