I am getting a similar ajax error on a mashup with about 100 icons http://www.ontheqt.ie – memory is being requested to >64Mb. Currently, the error is only being generated with the dashboard open, but I know from the way it has gone so far that a few more posts will cause the error without the dashboard open.
Can you help here please as there seems to be a lot of overhead for a relatively small number of icons.
I am using MapPress on shared hosting at the moment and have run into the same problem with >50 posts being displayed. If I were to move the site to its own server, what memory would I need to specify or is there something I could get the current host to do with php.ini?