Currently after a day of uptime, with both SM and TB loaded, I have 253 MBs of free low memory. I really should be marking some of the DLLs in @UNIXROOT\usr\lib to load high.
Since I rarely use TB, or SM, it is easy enough to stop FF first (if I don't the second one simply doesn't start). I am puzzled why you have so much more free shared memory space, although that is close to what I see on my laptops. It is my main machine that has the problem, but I haven't been able to isolate what the difference is. During boot, it is XCenter that eats the most, and that is 40 Mb (after I removed all of the DLLs that I don't actually use). I have a second XCenter, but it only uses an additional 2 Mb.
I wonder what part of clamd is loaded high and if that could be triggering a problem?
I don't know. I used ClamD for a long time, until I started having severe low shared memory problems (about 3 years ago). After I discovered that the latest version loads high, I started using it again. It doesn't seem to use any low shared memory, but, according to Theseus, it uses about 300 Mb of shared memory space, which I assume is in high memory. I believe that most of it is the database. I don't know why that would need to be in shared memory space anyway. FWIW, I was having this problem long before I started using ClamD again.
Are you relying mail to Win boxes? Otherwise I can't see any point in running clamd, which probably uses resources.
I do forward e-mail sometimes, and I will admit that ClamDscan rarely actually finds anything to complain about, but I don't like to expose windows users to any more problems than they already have, so I scan all incoming mail. The only resources that it seems to use (other than high shared memory) is private memory, some disk space, and a few machine cycles.