Subscriptions execution timing-out

Hello, I am sorry if this has been posted somewhere else, I tried hard to find the solution, but could not find it around here, so I am opening a new issue.

What happen is the following: I had a website running in a server, with Subscriptions module enabled. Everything was running smoothly: I had around 350 subscribers, so that would the amount of e-mails the system would send every time CRON ran. I recently migrated the website to Dreamhost and the mails stopped being sent. I noticed CRON was not running properly (The error said that I was trying to run CRON while it was already running). When I disabled the Subscriptions module, CRON would run successfully.

When I enable Subscriptions again, and run CRON, the site sends some of the e-mails and then, all of a sudden, I am redirected to a Page not found. Not all the e-mails were sent and when I try to run cron again, I give the same message that it is already running.

My conclusion was that the new host is timing out Subscriptions and thus not all the e-mails are being sent. I would like to know if there is a way of dealing with this, maybe raising the timing out or allowing just a certain number of e-mails being sent by Subscriptions each time cron runs?

Thank you for your help.

Daniela