I seem to have the same problem on this computer too. If it do wait for the first screen to go away i nodice it hangs for a bit on every little thing. If you highlight an option (for the first time) it hangs for a few seconds. if you go into the options it hangs for a good minitue. If you change or highlight a setting it hangs for a second.
Now this is the olny mod for freespace (out of Wing commander, Babylon project and freespace 2) where i have this problem. Looking through all the files I nodice that BtRL has one thing what the others don't. A big honking VP file which has everything... (every other mod has split its VPs into sound, core, effects etc....) I don't know if this really hads anything to do with the problem but it seems plusable as the program has to go through the file for every little thing.
If i alt+tab then ctrl+alt+del out i nodice that the CPU usage is at 100% but the computer dosen't look like its doing anything (no blinking light on the box or anything)
anyway here is the FS2 log file and system specs
DEBUG SPEW: No debug_filter.cfg found, so only general, error, and warning
categories can be shown and no debug_filter.cfg info will be saved.
Passed cmdline options:
Building file index...
Searching root 'E:\games\btrl\demo\'
Searching root pack 'E:\games\btrl\demo\z_missions_BtRLDemo.vp'
Searching root pack 'E:\games\btrl\demo\z_root_BtRLDemo.vp'
Searching root 'f:\'
Found 4 roots and 3261 files.
Setting language to English
Using 'Generic Software' as OpenAL sound device...
OpenAL Vendor : Creative Labs Inc.
OpenAL Renderer : Software
OpenAL Version : 1.1
... OpenAL successfully initialized!
GR_CPU: Family 15, MMX=Yes
Initializing OpenGL graphics device at 1024x768 with 32-bit color...
Requested WGL Video values = R: 8, G: 8, B: 8, depth: 24, double-buffer: 1
Actual WGL Video values = R: 8, G: 8, B: 8, depth: 24, double-buffer: 1
OpenGL Vendor : NVIDIA Corporation
OpenGL Renderer : GeForce FX 5500/PCI/SSE2
OpenGL Version : 2.0.3
Using extension "GL_EXT_fog_coord".
Using extension "GL_ARB_multitexture".
Using extension "GL_ARB_texture_env_add".
Using extension "GL_ARB_texture_compression".
Using extension "GL_EXT_texture_compression_s3tc".
Using extension "GL_EXT_texture_filter_anisotropic".
Using extension "GL_ARB_texture_env_combine".
Using extension "GL_EXT_compiled_vertex_array".
Using extension "GL_EXT_draw_range_elements".
Using extension "GL_ARB_texture_mirrored_repeat".
Unable to find extension "GL_ARB_texture_non_power_of_two".
Using extension "GL_ARB_vertex_buffer_object".
Using extension "GL_ARB_pixel_buffer_object".
Unable to find extension "GL_APPLE_client_storage".
Using extension "GL_SGIS_generate_mipmap".
Using extension "GL_EXT_framebuffer_object".
Using extension "GL_ARB_texture_rectangle".
Using extension "GL_EXT_bgra".
Using extension "GL_ARB_texture_cube_map".
Using extension "GL_EXT_texture_lod_bias".
Found special extension function "wglSwapIntervalEXT".
Max texture units: 4
Max elements vertices: 4096
Max elements indices: 4096
Max texture size: 4096x4096
Can use compressed textures: YES
Texture compression available: YES
Using trilinear texture filter.
... OpenGL init is complete!
Size of bitmap info = 705 KB
Size of bitmap extra info = 40 bytes
ANI cursorweb with size 20x20 (37.5% wasted)
GRAPHICS: Initializing default colors...
OpenGL: Created 512x512 FBO!
OpenGL: Reusing 512x512 FBO!
SCRIPTING: Beginning initialization sequence...
SCRIPTING: Beginning Lua initialization...
LUA: Opening LUA state...
LUA: Initializing base Lua libraries...
LUA: Performing global function/(library/object) name repeat check...
LUA: Performing library/object name repeat check...
LUA: Performing object/object name repeat check...
LUA: Performing library/library name repeat check...
LUA: Initializing library functions...
LUA: Initializing object functions...
SCRIPTING: Beginning main hook parse sequence....
Wokka! Error opening file (scripting.tbl)!
Unable to parse scripting.tbl! Code = 5.
SCRIPTING: Inititialization complete.
Using high memory settings...
Wokka! Error opening file (interface.tbl)!
Unable to parse interface.tbl!
cf_get_file_list_preallocated looking for type=7, filter="*-sdf.tbm"
ANI 2_radar1 with size 170x170 (33.6% wasted)
Windoze reported 16 joysticks, we found 0
Current soundtrack set to -1 in event_music_reset_choices
cf_get_file_list_preallocated looking for type=7, filter="*-mus.tbm"
cf_get_file_list_preallocated looking for type=7, filter="*-mfl.tbm"
Wokka! Error opening file (armor.tbl)!
Unable to parse armor.tbl!
cf_get_file_list_preallocated looking for type=7, filter="*-amr.tbm"
cf_get_file_list_preallocated looking for type=7, filter="*-wxp.tbm"
BMPMAN: Found EFF (exp20.eff) with 64 frames at 35 fps.
BMPMAN: Found EFF (ExpMissileHit1.eff) with 83 frames at 30 fps.
BMPMAN: Found EFF (M_trail_particle.eff) with 17 frames at 20 fps.
BMPMAN: Found EFF (bomb_flare.eff) with 86 frames at 24 fps.
Windows XP SP2
Intel Pentium 4 2.40 GHz
1 GB RAM
Nvidia GeForce FX 5500 256 MB (updated to latest version)
BTW the pentium 4 processor is not a dual core (to the best of my knowlege)