Submit of action on cmsb hangs on record num

Hi,

Every now and then (say 1 / 5) of times I submit an action on any CMSB install (save a record for example), the resulting page is:

http://xxxxxx/cmsAdmin/admin.php?

with the page ONLY displaying the record number. The source of that page is also ONLY the record number.

It's like it's getting stuck half way through the process to push the action.

I cannot detect any specific pattern, or cause (seems to happen randomly).

And also happens on different CMSB install locations, be it on different servers, on my localhost, all places.

It started happening about a month ago...

Am using Firefox 3.6.12 (latest) and have done the usual cache clear etc.

Anyone else have this problem, ever?!

Cheers