Why is my iphone (jailbroken with Snowbreeze) stuck on the boot screen?

I have an iphone 3g that has been working fine. I had it jailbroken about a year ago with Snowbreeze (not sure which version) without any glitches ot problems. I stopped using the phone about a month ago because I got a new phone, so it sat unused during that time. I decided to charge it up the ther day to let my son use it and upon pluggin it in, it went to the Snowflake boot screen and got stuck there. It has been on this screen for 2 days now. I understand that most versions of Snowbreeze are tethered, so perhaps this is the issues, but I'm not sure. So I'm asking for help with someone with Snowbreeze/jailbreak expereince. What could be causing this issue and is there a way to get it to complete the boot process without losing the information already contained in the phone (contacts, messages, etc)? Thanks for you time and help.

Added (1). Thanks Ahmad. I tried the manual reboot with the home and power button. It went back to the boot screen and froze there again. The only time it leaves the Snowflake boot screen is when the power runs all of the way down and it give your the battery icon with the red warning. Once you plug it back in to a charger, it returns to the snowflake icon.

Try to reboot by pressing both the power button and the home button and keep holding them till your phone turn off. Then press the power button to turn it on again and see if it will work.