This symptom commonly occurs when the first field of the uptmagent file is not unique.
The first field (the secretpassword) is used as a line identifier to decide which script should be launched.
If you are experiencing this issue, check your .uptmpasswd file to ensure that a *unique* password is used for each script. For example:
pass1 /opt/uptime-agent/my-scripts/script1.sh pass2 /opt/uptime-agent/my-scripts/script2.pl