You're not specifying the path to the PHP 5+ executable in the command. Also I hope you are not running these daemons (long-running background process PHP scripts that leak memory according to the documentation) on a shared server. From DreamHost Terms of Service:
"Servers are shared with other customers, and as such IRC-related activities or severely CPU intensive CGI scripts (e.g. chat scripts, scripts which have bugs causing them to not close properly after being run, etc.) are not encouraged. Any application that listens for inbound network connections (even if the application would otherwise be allowed) are not permitted. BitTorrent clients, proxy servers/scripts, IRC bots and bouncers (BNC) specifically may not be run on any DreamHost Web Hosting server. If your processes are adversely affecting server performance disproportionately DreamHost Web Hosting reserves the right to negotiate additional charges with the Customer and/or the discontinuation of the offending processes."
And from the Laconica README:
"Some activities that Laconica needs to do, like broadcast OMB, SMS, and XMPP messages, can be 'queued' and done by off-line bots instead. For this to work, you must be able to run long-running offline processes, either on your main Web server or on another server you control. (Your other server will still need all the above prerequisites, with the exception of Apache.) Installing on a separate server is probably a good idea for high-volume sites."
"Note that these queue daemons are pretty raw, and need your care. In particular, they leak memory, and you may want to restart them on a regular (daily or so) basis with a cron job. Also, if they lose the connection to the XMPP server for too long, they'll simply die. It
may be a good idea to use a daemon-monitoring service, like 'monit',
to check their status and keep them running."
Customer since 2000 openvein.org