trouble with bounces

I have just looked at my qmail-debug logs which is showing the message:

warning: trouble injecting bounce message, will try later.

this is coming up a lot... like several of them in the span of a second...

they started yesterday some time which coincides with some problems I was
having with my swap partition. ie; the drive was corrupted and caused me no
end of problems with my web server, so processes with screwed up names,
qmail, etc... I restarted everything that seemed to crap out and it all
seems to be going OK, but the system is quite low on resources... it floats
between 3 and 20Mb of RAM free out of 384Mb...

I had to kill the swap partition till we can get a new HD to replace the
swap drive, so basically, it may have stemmed from a memory corruption...

it's quite odd, any advice or opinions welcome.

ta.

--
Spiro Harvey
Linux Systems Engineer
A.Net Communications     /      ( http://www.anet.co.nz )