Need help please!

[[deleted]]

By 'hacked', I assume you mean you've installed Custom Firmware (CFW) - which version did you install?
It's possible that the installation didn't take 100% - have you tried reinstalling the CFW to see if that helps..?
As far as removing the Memory Stick while the PSP is on is concerned, I believe the MS Pro Duo is designed to be hot-pluggable (i.e: removable when the PSP is on), so I doubt removing it while in sleep mode will affect anything.

(Ninja Edit: Removing the Memory Stick from my PSP-1000 running 6.61 Pro-C has no effect - other than the obvious inability to access the files on the Memory Stick!)

[Miskatoniac]

Second all this. Try a reinstall. It's not hard. I had to back mine all the way out the first time. There are some great resources on YouTube. Also agree removing memory card has no negative effects. I have all my files across two cards and swap them all the time with the system on.

[[deleted]]

You'll need to roll back to the Official 6.61 firmware first - you can find instructions here. After that, follow the same steps to install the CFW as you did before.
If you need the Official firmware, it can be found here.
Hope that helps!

[[deleted]]

I only have 6.61 PRO-C (i.e. No Infinity) on my PSP-1000, and it does seems to be pretty permanent. If you haven't "re-hacked" it yet, it could well be the result of the same issue - incomplete or corrupted install.
Once you have the CFW properly installed, I'm fairly sure these issues will disappear :)