Apache Error !!! Help !!!

Apache Error !!! Help !!! -- Linux Enterprise Application-Linux server application information. For details, refer to the following section. Note: 10.50.10.45 indicates the firewall address. If you disable the firewall, the IP address of the Internet is displayed !!!
The Error Log content is as follows:
[Tue Mar 18 19:12:41 2008] [error] [client 10.50.10.45] request failed: error reading the headers
[Tue Mar 18 19:12:42 2008] [error] [client 10.50.10.45] Invalid method in request \ xc9I; \ x9ez \ xdd
[Tue Mar 18 19:12:44 2008] [error] [client 10.50.10.45] Invalid method in request \ xaf \ xe2K \ xd4 \ x82Z \ x05 \ xf8 \ xcf \ x01 \ xe3y \ xcd \ xa1 \ x98L [\ xaca \ xdc ~ E \ xac \ x9ca \ xab + \ x91 \ xae \ xb2 \ xd3 \ x03 & \ xc5Z \ x8d & \ xc5 \ xbfX6; \ xe6 \ xb6KW \ xa5 \ xf1 # \ xea '\ xb8 \ x93 \ x15g \ xa34 _ \ x99
[Tue Mar 18 19:12:57 2008] [error] [client 10.50.10.45] request failed: error reading the headers
[Tue Mar 18 19:13:04 2008] [error] [client 10.50.10.45] request failed: error reading the headers
[Tue Mar 18 19:13:16 2008] [error] [client 10.50.10.45] request failed: error reading the headers
[Tue Mar 18 19:13:19 2008] [error] [client 10.50.10.45] Invalid method in request \ xc2 \ x8eD \ x8b \ x9f \ xbcw \ xb2 * \ x82 \ xae \ xf29
[Tue Mar 18 19:13:24 2008] [error] [client 10.50.10.45] Invalid URI in request \ xa3b & 9 \ xee \ x7f] K02 \ x10ekqN \ xe8 \ xe1 \ x9a \ xe6 \ x90j

The connection log is as follows:
0.50.10.45--[18/Mar/2008: 19: 12: 41 + 0800] "\ xde \ x0c \ x1b \ xf9 \ x80 \ x82 \ x17 \ xb6 \ x07 \ x86 \ xd5 \ xe9 & \ xd1hs \" # \ xdf \ t \ xdb \ xdb3s * \ xf7 \ xce \ x85 \ x1f | \ x11 \ x031 \ xb8 \ xff \ x02 \ xedb \ xed \ xa0Y \ "\ xef \ x9aQmm \ xe01 \ xa0 | "400 392
10.50.10.45--[18/Mar/2008: 19: 12: 42 + 0800] "\ xc9I; \ x9ez \ xdd" 501 218
10.50.10.45--[18/Mar/2008: 19: 12: 44 + 0800] "\ xaf \ xe2K \ xd4 \ x82Z \ x05 \ xf8 \ xcf \ x01 \ xe3y \ xcd \ xa1 \ x98L [\ xaca \ xdc ~ E \ xac \ x9ca \ xab + \ x91 \ xae \ xb2 \ xd3 \ x03 & \ xc5Z \ x8d & \ xc5 \ xbfX6; \ xe6 \ xb6KW \ xa5 \ xf1 # \ xea '\ xb8 \ x93 \ x15g \ xa34 _ \ x99 "501 279
10.50.10.45--[18/Mar/2008: 19: 12: 45 + 0800] "GET/HTTP/1.1" 200 44
10.50.10.45--[18/Mar/2008: 19: 12: 57 + 0800] "\ x18 \ x18/\ xd6 * \ xd2 \ xb1 ~ \ Xb0xg \ x9d \ x03 \ x88) \ xb1n \ "\ x19 \ xe5 \ xfc \ xc6 \ xbcp9 (\ xcd (\ x02C \ xaf \ xa4 \ xe2H} \ x16 \ x8fT {\ xae \ x97 \ xa5 \ xac \ xb6 \ x1cq \ xe9 \ xbfe) \ xb4 \ xe6s \ xf9U \ v \ xab \ xd7 \ x92 \ xed \ xa6 % <\ xc9j "400 310
10.50.10.45--[18/Mar/2008: 19: 13: 04 + 0800] "\ x0f1 \ x87 <\ x15 \ xa6 \" ww \ xdb \ xe8? \ Xf1 \ r \ xab \ x16 \ xf9 \ x809> y-\ x07 \ xa2 \ xb7 \ xd3i \ x82 \ xcbV \ x85l * \ xfd \ x12 \ xdb \ xef \ xbf \ x1aJ \ x84 \ r \ x1f ~ \ Xe7> \ x8c \ x1b \ xc1 \ xa5 \ x95 \ v \ x1aE \ x82 \ xbe \ x05 \ xa8 \ x84 \ xd1 \ x1e \ xf1 \ x1e \ x12T \ x0fq \ xfe \ xb9, \ xa2 \ xb3 \ xbe \ xd02 \ xa1e \ x1f \ xf4 \ xb9 \ xf9 \ x84 \ xd6z \ x01 \ xd6 \ x98 \ x94Ry \ x0eQI \ xd9 \ xe9 {g. \ xe6 \ x87r \ xb7 \ x88 'B} \ xd9 \ x8cN \ xe74 \ xf3 \ xf3 \ xae \ xfc \ x84 \ xc6 \ xe3 \ x8dy) 4s \ x82 \ x1ck \ xdbhV7F \ xf1 \ x95/\ x85 \ x052 \ x14 \ xe1 \ x0e \ xf8V \ x9a \ xa56 \ xda \ x93j \ x13 \ xfbK3 \ "\ xcf \ x0fj6 \ xabn \ xb0x \ xe9 \ xee \ xc6 \ xb6 \ xe8 \ xfd \ xae \ xfeU * \ rl \ xa9 \ x95 \ xd4 @ \ xf3 \ xa 4 \ x1f3 \ xd8 \ xf8 ^ \ x0c \ xd8 \ xa0 \ xb2n \ xd3 \ x8c \ x9a \ xf4 \ xcbD \ xce \ x80 \ xeb \ xdak \ xcf \ xc8 \ x1cQQ \ xe8 \ x0f \ xc98 \ x81 \ x99l \ xcf \ x82 ~ @ \ X0e \ xd7 \ x8e # k \ xe9 \ x 1cm \ xf2e \ xb1 \ xd1 \ x98? \ X02 \ x84 \ xcd \ xf6 \ xa1P \ x19 \ xef \ xcdG "400 441
10.50.10.45--- [18/Mar/2008: 19: 13: 16 + 0800] "\ x16 \ xdbT \ x126 \ xcal \ xa0 \ x8fW \ xec9G \ xba \ x19 \ x0e \ x95V \ xb9o \ xba \ xda \ xa3Hb \ xc0 \ xf5 \ x13p \ r \ B \ x9f \ xbe \ xc7J \ x11buG \ x8f5 \ xc4 \ xac \ xf6 \ xba \ xb5 \ xb3 \ x98 \ xd4 \ xa4 * W + \ xc4 \ xc3 '\ xc3 \ x17 \ x8e \ xc2 \ x8d \ xfe = \ xc4 \ x91 \ xe9 \ x8c \ x9a \ x01jSu \ xe3 \ x1a \ xa5 \ xf9 \ xb2 \ x01 \ xcb7 \ x8a \ x19 \ xbe7mr \ x90gL \ x87 \ xf6 \ xe2_4 \ x99F '* \ x90 \ xc0 \ xfb \ x16 \ xd3 \ x9d * \ xe74 \ xb3.D \ x1f % }\ xa9; 6 \ x18 \ x0c \ xac \ x8a! R0 \ x19d \ "\ xf7 {RV \ xa2 \ xe03 \ xc4c \ xc0m \ xcdb \ xb3 \ x03 \ xf8 _ \ x89 \ x9e \ x98 \ x97F \ xe7 \ xedO: \ xf5B \ x14 \ xe2 ^ % L \ xd8 \ xe0 \ xb0 \ xb6 \ xb1P \ xb1 \ xfd: \ xd4 \ t \ x8e \ x01RR \ xa7 \ x17 (\ xc5 \ xb1 \ x15 \ x1eZ \ xd0] \ x980 \ xb8 \ xa2 \ x110 \ xc2 \ xab \ xc4 \ xee? S \ xac \ xcf \ x0c \ xd5 \ xafqgF \ x17G "400 413
10.50.10.45--- [18/Mar/2008: 19: 13: 19 + 0800] "\ xc2 \ x8eD \ x8b \ x9f \ xbcw \ xb2 * \ x82 \ xae \ xf29" 501 225
10.50.10.45--- [18/Mar/2008: 19: 13: 24 + 0800] "\ xa3b & 9 \ xee \ x7f] K02 \ x10ekqN \ xe8 \ xe1 \ x9a \ xe6 \ x90j" 400 226


Server environment:
The Intranet ip address maps ports on the vro to the server.
Centos 1, 5.1
Apache2.2.8 compiled and installed!

Google's result is that someone in the network uses p2p software to use port 80! No solution!
Changed the apache listening port to 88!
How can I solve this problem! Thank you.