I am currently using a justhost shared host package with priority support, ssh and an enhanced server pack which apparently means a faster server and more simultaneous ftps.

I am currently with 1 oxwall and 1 wordpress install being suspended because of excessive resource usage.  The site has been up since JAN2011 and only now am I getting these suspensions.  This has been since 1.2.5

my cron runs ever 15 mins.  There aren't many users active :(

What I have noticed is when I install a backup of the site in a xampp environment at home and look at the live site, when I use mysql administrator and check server health on the xampp site, when there is no one logged in, bandwidth, sql queries and cache are all minimal.  When I check my live site db, it seems to have loads of sql activity.

Oxwall IM was using resource on both sites so when I disabled it on both sites that seemed to make a difference.

No reasons yet, hosters are vague in their responses.