Problem with PayPal error 77 after upgrade - http server software reset fixes

[osdmarine]

I recently upgraded from 1.3.9h to 1.5.5 and took lots of work but my site is working now. The only constant issue I'm having is a problem with PayPal access. I know it is a server issue with my local hosting company but he can't seem to figure it out so I'm hoping someone here can help me point him in the right direction.
As soon as I made the new upgrade active, I immediately started getting paypal error 77 when people try checking out which is an error with the site not being able to contact paypal. This never happened with the old version. When I upgraded I also upgraded the PayPal Express Checkout module to the most current too. So my hosting guy increased the php input variables to 10x what every other site he hosts uses (I'm the only one using zen cart) and that temporarily fixed it. Now he has to reset the http software (not server) and it fixes it for a little while then comes back again. I don't know much about this stuff but its like something is filling up and resetting empties it. I figure the new version has better security so can that be having something to do with it? I searched the forum and no one else seems to be having this issue so figure it has to be something with the server which I have no access to and have no clue about how those work. Anyone have a suggestion where to point him to look and/or how to fix this?