[SOLVED] Change php to 5.2.10,then panel can`t visit report HTTP500

[freed1985]

Today,I reinstall my php with version 5.2.10(old php is 5.3.2)

Then I can visit the page in vhosts.
But now I can`t visit my panel ,it reports HTTP500 error.
Why?

Code:

123.191.58.175 - - [19/Mar/2010:05:36:29 -0700] "GET / HTTP/1.1" 500 - "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; QQPinyin 689)"
123.191.58.175 - - [19/Mar/2010:05:36:29 -0700] "GET / HTTP/1.1" 500 - "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; QQPinyin 689)"
116.3.187.222 - - [19/Mar/2010:05:41:18 -0700] "GET / HTTP/1.1" 500 - "-" "Opera/9.80 (Windows NT 6.1; U; zh-cn) Presto/2.2.15 Version/10.10"
116.3.187.222 - - [19/Mar/2010:05:41:18 -0700] "GET / HTTP/1.1" 500 - "-" "Opera/9.80 (Windows NT 6.1; U; zh-cn) Presto/2.2.15 Version/10.10"
116.3.187.222 - - [19/Mar/2010:05:41:24 -0700] "GET / HTTP/1.1" 500 - "-" "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0)"
116.3.187.222 - - [19/Mar/2010:05:41:24 -0700] "GET / HTTP/1.1" 500 - "-" "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0)"

I use ispCP1.0.4 on CentOS5.4